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diff --git a/www/wiki/includes/upload/UploadBase.php b/www/wiki/includes/upload/UploadBase.php
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+<?php
+/**
+ * Base class for the backend of file upload.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Upload
+ */
+use MediaWiki\MediaWikiServices;
+
+/**
+ * @defgroup Upload Upload related
+ */
+
+/**
+ * @ingroup Upload
+ *
+ * UploadBase and subclasses are the backend of MediaWiki's file uploads.
+ * The frontends are formed by ApiUpload and SpecialUpload.
+ *
+ * @author Brion Vibber
+ * @author Bryan Tong Minh
+ * @author Michael Dale
+ */
+abstract class UploadBase {
+	/** @var string Local file system path to the file to upload (or a local copy) */
+	protected $mTempPath;
+	/** @var TempFSFile|null Wrapper to handle deleting the temp file */
+	protected $tempFileObj;
+
+	protected $mDesiredDestName, $mDestName, $mRemoveTempFile, $mSourceType;
+	protected $mTitle = false, $mTitleError = 0;
+	protected $mFilteredName, $mFinalExtension;
+	protected $mLocalFile, $mStashFile, $mFileSize, $mFileProps;
+	protected $mBlackListedExtensions;
+	protected $mJavaDetected, $mSVGNSError;
+
+	protected static $safeXmlEncodings = [
+		'UTF-8',
+		'ISO-8859-1',
+		'ISO-8859-2',
+		'UTF-16',
+		'UTF-32',
+		'WINDOWS-1250',
+		'WINDOWS-1251',
+		'WINDOWS-1252',
+		'WINDOWS-1253',
+		'WINDOWS-1254',
+		'WINDOWS-1255',
+		'WINDOWS-1256',
+		'WINDOWS-1257',
+		'WINDOWS-1258',
+	];
+
+	const SUCCESS = 0;
+	const OK = 0;
+	const EMPTY_FILE = 3;
+	const MIN_LENGTH_PARTNAME = 4;
+	const ILLEGAL_FILENAME = 5;
+	const OVERWRITE_EXISTING_FILE = 7; # Not used anymore; handled by verifyTitlePermissions()
+	const FILETYPE_MISSING = 8;
+	const FILETYPE_BADTYPE = 9;
+	const VERIFICATION_ERROR = 10;
+	const HOOK_ABORTED = 11;
+	const FILE_TOO_LARGE = 12;
+	const WINDOWS_NONASCII_FILENAME = 13;
+	const FILENAME_TOO_LONG = 14;
+
+	/**
+	 * @param int $error
+	 * @return string
+	 */
+	public function getVerificationErrorCode( $error ) {
+		$code_to_status = [
+			self::EMPTY_FILE => 'empty-file',
+			self::FILE_TOO_LARGE => 'file-too-large',
+			self::FILETYPE_MISSING => 'filetype-missing',
+			self::FILETYPE_BADTYPE => 'filetype-banned',
+			self::MIN_LENGTH_PARTNAME => 'filename-tooshort',
+			self::ILLEGAL_FILENAME => 'illegal-filename',
+			self::OVERWRITE_EXISTING_FILE => 'overwrite',
+			self::VERIFICATION_ERROR => 'verification-error',
+			self::HOOK_ABORTED => 'hookaborted',
+			self::WINDOWS_NONASCII_FILENAME => 'windows-nonascii-filename',
+			self::FILENAME_TOO_LONG => 'filename-toolong',
+		];
+		if ( isset( $code_to_status[$error] ) ) {
+			return $code_to_status[$error];
+		}
+
+		return 'unknown-error';
+	}
+
+	/**
+	 * Returns true if uploads are enabled.
+	 * Can be override by subclasses.
+	 * @return bool
+	 */
+	public static function isEnabled() {
+		global $wgEnableUploads;
+
+		if ( !$wgEnableUploads ) {
+			return false;
+		}
+
+		# Check php's file_uploads setting
+		return wfIsHHVM() || wfIniGetBool( 'file_uploads' );
+	}
+
+	/**
+	 * Returns true if the user can use this upload module or else a string
+	 * identifying the missing permission.
+	 * Can be overridden by subclasses.
+	 *
+	 * @param User $user
+	 * @return bool|string
+	 */
+	public static function isAllowed( $user ) {
+		foreach ( [ 'upload', 'edit' ] as $permission ) {
+			if ( !$user->isAllowed( $permission ) ) {
+				return $permission;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Returns true if the user has surpassed the upload rate limit, false otherwise.
+	 *
+	 * @param User $user
+	 * @return bool
+	 */
+	public static function isThrottled( $user ) {
+		return $user->pingLimiter( 'upload' );
+	}
+
+	// Upload handlers. Should probably just be a global.
+	private static $uploadHandlers = [ 'Stash', 'File', 'Url' ];
+
+	/**
+	 * Create a form of UploadBase depending on wpSourceType and initializes it
+	 *
+	 * @param WebRequest &$request
+	 * @param string|null $type
+	 * @return null|UploadBase
+	 */
+	public static function createFromRequest( &$request, $type = null ) {
+		$type = $type ? $type : $request->getVal( 'wpSourceType', 'File' );
+
+		if ( !$type ) {
+			return null;
+		}
+
+		// Get the upload class
+		$type = ucfirst( $type );
+
+		// Give hooks the chance to handle this request
+		$className = null;
+		Hooks::run( 'UploadCreateFromRequest', [ $type, &$className ] );
+		if ( is_null( $className ) ) {
+			$className = 'UploadFrom' . $type;
+			wfDebug( __METHOD__ . ": class name: $className\n" );
+			if ( !in_array( $type, self::$uploadHandlers ) ) {
+				return null;
+			}
+		}
+
+		// Check whether this upload class is enabled
+		if ( !call_user_func( [ $className, 'isEnabled' ] ) ) {
+			return null;
+		}
+
+		// Check whether the request is valid
+		if ( !call_user_func( [ $className, 'isValidRequest' ], $request ) ) {
+			return null;
+		}
+
+		/** @var UploadBase $handler */
+		$handler = new $className;
+
+		$handler->initializeFromRequest( $request );
+
+		return $handler;
+	}
+
+	/**
+	 * Check whether a request if valid for this handler
+	 * @param WebRequest $request
+	 * @return bool
+	 */
+	public static function isValidRequest( $request ) {
+		return false;
+	}
+
+	public function __construct() {
+	}
+
+	/**
+	 * Returns the upload type. Should be overridden by child classes
+	 *
+	 * @since 1.18
+	 * @return string
+	 */
+	public function getSourceType() {
+		return null;
+	}
+
+	/**
+	 * Initialize the path information
+	 * @param string $name The desired destination name
+	 * @param string $tempPath The temporary path
+	 * @param int $fileSize The file size
+	 * @param bool $removeTempFile (false) remove the temporary file?
+	 * @throws MWException
+	 */
+	public function initializePathInfo( $name, $tempPath, $fileSize, $removeTempFile = false ) {
+		$this->mDesiredDestName = $name;
+		if ( FileBackend::isStoragePath( $tempPath ) ) {
+			throw new MWException( __METHOD__ . " given storage path `$tempPath`." );
+		}
+
+		$this->setTempFile( $tempPath, $fileSize );
+		$this->mRemoveTempFile = $removeTempFile;
+	}
+
+	/**
+	 * Initialize from a WebRequest. Override this in a subclass.
+	 *
+	 * @param WebRequest &$request
+	 */
+	abstract public function initializeFromRequest( &$request );
+
+	/**
+	 * @param string $tempPath File system path to temporary file containing the upload
+	 * @param int $fileSize
+	 */
+	protected function setTempFile( $tempPath, $fileSize = null ) {
+		$this->mTempPath = $tempPath;
+		$this->mFileSize = $fileSize ?: null;
+		if ( strlen( $this->mTempPath ) && file_exists( $this->mTempPath ) ) {
+			$this->tempFileObj = new TempFSFile( $this->mTempPath );
+			if ( !$fileSize ) {
+				$this->mFileSize = filesize( $this->mTempPath );
+			}
+		} else {
+			$this->tempFileObj = null;
+		}
+	}
+
+	/**
+	 * Fetch the file. Usually a no-op
+	 * @return Status
+	 */
+	public function fetchFile() {
+		return Status::newGood();
+	}
+
+	/**
+	 * Return true if the file is empty
+	 * @return bool
+	 */
+	public function isEmptyFile() {
+		return empty( $this->mFileSize );
+	}
+
+	/**
+	 * Return the file size
+	 * @return int
+	 */
+	public function getFileSize() {
+		return $this->mFileSize;
+	}
+
+	/**
+	 * Get the base 36 SHA1 of the file
+	 * @return string
+	 */
+	public function getTempFileSha1Base36() {
+		return FSFile::getSha1Base36FromPath( $this->mTempPath );
+	}
+
+	/**
+	 * @param string $srcPath The source path
+	 * @return string|bool The real path if it was a virtual URL Returns false on failure
+	 */
+	public function getRealPath( $srcPath ) {
+		$repo = RepoGroup::singleton()->getLocalRepo();
+		if ( $repo->isVirtualUrl( $srcPath ) ) {
+			/** @todo Just make uploads work with storage paths UploadFromStash
+			 *  loads files via virtual URLs.
+			 */
+			$tmpFile = $repo->getLocalCopy( $srcPath );
+			if ( $tmpFile ) {
+				$tmpFile->bind( $this ); // keep alive with $this
+			}
+			$path = $tmpFile ? $tmpFile->getPath() : false;
+		} else {
+			$path = $srcPath;
+		}
+
+		return $path;
+	}
+
+	/**
+	 * Verify whether the upload is sane.
+	 * @return mixed Const self::OK or else an array with error information
+	 */
+	public function verifyUpload() {
+		/**
+		 * If there was no filename or a zero size given, give up quick.
+		 */
+		if ( $this->isEmptyFile() ) {
+			return [ 'status' => self::EMPTY_FILE ];
+		}
+
+		/**
+		 * Honor $wgMaxUploadSize
+		 */
+		$maxSize = self::getMaxUploadSize( $this->getSourceType() );
+		if ( $this->mFileSize > $maxSize ) {
+			return [
+				'status' => self::FILE_TOO_LARGE,
+				'max' => $maxSize,
+			];
+		}
+
+		/**
+		 * Look at the contents of the file; if we can recognize the
+		 * type but it's corrupt or data of the wrong type, we should
+		 * probably not accept it.
+		 */
+		$verification = $this->verifyFile();
+		if ( $verification !== true ) {
+			return [
+				'status' => self::VERIFICATION_ERROR,
+				'details' => $verification
+			];
+		}
+
+		/**
+		 * Make sure this file can be created
+		 */
+		$result = $this->validateName();
+		if ( $result !== true ) {
+			return $result;
+		}
+
+		$error = '';
+		if ( !Hooks::run( 'UploadVerification',
+			[ $this->mDestName, $this->mTempPath, &$error ], '1.28' )
+		) {
+			return [ 'status' => self::HOOK_ABORTED, 'error' => $error ];
+		}
+
+		return [ 'status' => self::OK ];
+	}
+
+	/**
+	 * Verify that the name is valid and, if necessary, that we can overwrite
+	 *
+	 * @return mixed True if valid, otherwise and array with 'status'
+	 * and other keys
+	 */
+	public function validateName() {
+		$nt = $this->getTitle();
+		if ( is_null( $nt ) ) {
+			$result = [ 'status' => $this->mTitleError ];
+			if ( $this->mTitleError == self::ILLEGAL_FILENAME ) {
+				$result['filtered'] = $this->mFilteredName;
+			}
+			if ( $this->mTitleError == self::FILETYPE_BADTYPE ) {
+				$result['finalExt'] = $this->mFinalExtension;
+				if ( count( $this->mBlackListedExtensions ) ) {
+					$result['blacklistedExt'] = $this->mBlackListedExtensions;
+				}
+			}
+
+			return $result;
+		}
+		$this->mDestName = $this->getLocalFile()->getName();
+
+		return true;
+	}
+
+	/**
+	 * Verify the MIME type.
+	 *
+	 * @note Only checks that it is not an evil MIME. The "does it have
+	 *  correct extension given its MIME type?" check is in verifyFile.
+	 *  in `verifyFile()` that MIME type and file extension correlate.
+	 * @param string $mime Representing the MIME
+	 * @return mixed True if the file is verified, an array otherwise
+	 */
+	protected function verifyMimeType( $mime ) {
+		global $wgVerifyMimeType;
+		if ( $wgVerifyMimeType ) {
+			wfDebug( "mime: <$mime> extension: <{$this->mFinalExtension}>\n" );
+			global $wgMimeTypeBlacklist;
+			if ( $this->checkFileExtension( $mime, $wgMimeTypeBlacklist ) ) {
+				return [ 'filetype-badmime', $mime ];
+			}
+
+			# Check what Internet Explorer would detect
+			$fp = fopen( $this->mTempPath, 'rb' );
+			$chunk = fread( $fp, 256 );
+			fclose( $fp );
+
+			$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
+			$extMime = $magic->guessTypesForExtension( $this->mFinalExtension );
+			$ieTypes = $magic->getIEMimeTypes( $this->mTempPath, $chunk, $extMime );
+			foreach ( $ieTypes as $ieType ) {
+				if ( $this->checkFileExtension( $ieType, $wgMimeTypeBlacklist ) ) {
+					return [ 'filetype-bad-ie-mime', $ieType ];
+				}
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Verifies that it's ok to include the uploaded file
+	 *
+	 * @return mixed True of the file is verified, array otherwise.
+	 */
+	protected function verifyFile() {
+		global $wgVerifyMimeType, $wgDisableUploadScriptChecks;
+
+		$status = $this->verifyPartialFile();
+		if ( $status !== true ) {
+			return $status;
+		}
+
+		$mwProps = new MWFileProps( MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer() );
+		$this->mFileProps = $mwProps->getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
+		$mime = $this->mFileProps['mime'];
+
+		if ( $wgVerifyMimeType ) {
+			# XXX: Missing extension will be caught by validateName() via getTitle()
+			if ( $this->mFinalExtension != '' && !$this->verifyExtension( $mime, $this->mFinalExtension ) ) {
+				return [ 'filetype-mime-mismatch', $this->mFinalExtension, $mime ];
+			}
+		}
+
+		# check for htmlish code and javascript
+		if ( !$wgDisableUploadScriptChecks ) {
+			if ( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
+				$svgStatus = $this->detectScriptInSvg( $this->mTempPath, false );
+				if ( $svgStatus !== false ) {
+					return $svgStatus;
+				}
+			}
+		}
+
+		$handler = MediaHandler::getHandler( $mime );
+		if ( $handler ) {
+			$handlerStatus = $handler->verifyUpload( $this->mTempPath );
+			if ( !$handlerStatus->isOK() ) {
+				$errors = $handlerStatus->getErrorsArray();
+
+				return reset( $errors );
+			}
+		}
+
+		$error = true;
+		Hooks::run( 'UploadVerifyFile', [ $this, $mime, &$error ] );
+		if ( $error !== true ) {
+			if ( !is_array( $error ) ) {
+				$error = [ $error ];
+			}
+			return $error;
+		}
+
+		wfDebug( __METHOD__ . ": all clear; passing.\n" );
+
+		return true;
+	}
+
+	/**
+	 * A verification routine suitable for partial files
+	 *
+	 * Runs the blacklist checks, but not any checks that may
+	 * assume the entire file is present.
+	 *
+	 * @return mixed True for valid or array with error message key.
+	 */
+	protected function verifyPartialFile() {
+		global $wgAllowJavaUploads, $wgDisableUploadScriptChecks;
+
+		# getTitle() sets some internal parameters like $this->mFinalExtension
+		$this->getTitle();
+
+		$mwProps = new MWFileProps( MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer() );
+		$this->mFileProps = $mwProps->getPropsFromPath( $this->mTempPath, $this->mFinalExtension );
+
+		# check MIME type, if desired
+		$mime = $this->mFileProps['file-mime'];
+		$status = $this->verifyMimeType( $mime );
+		if ( $status !== true ) {
+			return $status;
+		}
+
+		# check for htmlish code and javascript
+		if ( !$wgDisableUploadScriptChecks ) {
+			if ( self::detectScript( $this->mTempPath, $mime, $this->mFinalExtension ) ) {
+				return [ 'uploadscripted' ];
+			}
+			if ( $this->mFinalExtension == 'svg' || $mime == 'image/svg+xml' ) {
+				$svgStatus = $this->detectScriptInSvg( $this->mTempPath, true );
+				if ( $svgStatus !== false ) {
+					return $svgStatus;
+				}
+			}
+		}
+
+		# Check for Java applets, which if uploaded can bypass cross-site
+		# restrictions.
+		if ( !$wgAllowJavaUploads ) {
+			$this->mJavaDetected = false;
+			$zipStatus = ZipDirectoryReader::read( $this->mTempPath,
+				[ $this, 'zipEntryCallback' ] );
+			if ( !$zipStatus->isOK() ) {
+				$errors = $zipStatus->getErrorsArray();
+				$error = reset( $errors );
+				if ( $error[0] !== 'zip-wrong-format' ) {
+					return $error;
+				}
+			}
+			if ( $this->mJavaDetected ) {
+				return [ 'uploadjava' ];
+			}
+		}
+
+		# Scan the uploaded file for viruses
+		$virus = $this->detectVirus( $this->mTempPath );
+		if ( $virus ) {
+			return [ 'uploadvirus', $virus ];
+		}
+
+		return true;
+	}
+
+	/**
+	 * Callback for ZipDirectoryReader to detect Java class files.
+	 *
+	 * @param array $entry
+	 */
+	public function zipEntryCallback( $entry ) {
+		$names = [ $entry['name'] ];
+
+		// If there is a null character, cut off the name at it, because JDK's
+		// ZIP_GetEntry() uses strcmp() if the name hashes match. If a file name
+		// were constructed which had ".class\0" followed by a string chosen to
+		// make the hash collide with the truncated name, that file could be
+		// returned in response to a request for the .class file.
+		$nullPos = strpos( $entry['name'], "\000" );
+		if ( $nullPos !== false ) {
+			$names[] = substr( $entry['name'], 0, $nullPos );
+		}
+
+		// If there is a trailing slash in the file name, we have to strip it,
+		// because that's what ZIP_GetEntry() does.
+		if ( preg_grep( '!\.class/?$!', $names ) ) {
+			$this->mJavaDetected = true;
+		}
+	}
+
+	/**
+	 * Alias for verifyTitlePermissions. The function was originally
+	 * 'verifyPermissions', but that suggests it's checking the user, when it's
+	 * really checking the title + user combination.
+	 *
+	 * @param User $user User object to verify the permissions against
+	 * @return mixed An array as returned by getUserPermissionsErrors or true
+	 *   in case the user has proper permissions.
+	 */
+	public function verifyPermissions( $user ) {
+		return $this->verifyTitlePermissions( $user );
+	}
+
+	/**
+	 * Check whether the user can edit, upload and create the image. This
+	 * checks only against the current title; if it returns errors, it may
+	 * very well be that another title will not give errors. Therefore
+	 * isAllowed() should be called as well for generic is-user-blocked or
+	 * can-user-upload checking.
+	 *
+	 * @param User $user User object to verify the permissions against
+	 * @return mixed An array as returned by getUserPermissionsErrors or true
+	 *   in case the user has proper permissions.
+	 */
+	public function verifyTitlePermissions( $user ) {
+		/**
+		 * If the image is protected, non-sysop users won't be able
+		 * to modify it by uploading a new revision.
+		 */
+		$nt = $this->getTitle();
+		if ( is_null( $nt ) ) {
+			return true;
+		}
+		$permErrors = $nt->getUserPermissionsErrors( 'edit', $user );
+		$permErrorsUpload = $nt->getUserPermissionsErrors( 'upload', $user );
+		if ( !$nt->exists() ) {
+			$permErrorsCreate = $nt->getUserPermissionsErrors( 'create', $user );
+		} else {
+			$permErrorsCreate = [];
+		}
+		if ( $permErrors || $permErrorsUpload || $permErrorsCreate ) {
+			$permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsUpload, $permErrors ) );
+			$permErrors = array_merge( $permErrors, wfArrayDiff2( $permErrorsCreate, $permErrors ) );
+
+			return $permErrors;
+		}
+
+		$overwriteError = $this->checkOverwrite( $user );
+		if ( $overwriteError !== true ) {
+			return [ $overwriteError ];
+		}
+
+		return true;
+	}
+
+	/**
+	 * Check for non fatal problems with the file.
+	 *
+	 * This should not assume that mTempPath is set.
+	 *
+	 * @return mixed[] Array of warnings
+	 */
+	public function checkWarnings() {
+		$warnings = [];
+
+		$localFile = $this->getLocalFile();
+		$localFile->load( File::READ_LATEST );
+		$filename = $localFile->getName();
+		$hash = $this->getTempFileSha1Base36();
+
+		$badFileName = $this->checkBadFileName( $filename, $this->mDesiredDestName );
+		if ( $badFileName !== null ) {
+			$warnings['badfilename'] = $badFileName;
+		}
+
+		$unwantedFileExtensionDetails = $this->checkUnwantedFileExtensions( $this->mFinalExtension );
+		if ( $unwantedFileExtensionDetails !== null ) {
+			$warnings['filetype-unwanted-type'] = $unwantedFileExtensionDetails;
+		}
+
+		$fileSizeWarnings = $this->checkFileSize( $this->mFileSize );
+		if ( $fileSizeWarnings ) {
+			$warnings = array_merge( $warnings, $fileSizeWarnings );
+		}
+
+		$localFileExistsWarnings = $this->checkLocalFileExists( $localFile, $hash );
+		if ( $localFileExistsWarnings ) {
+			$warnings = array_merge( $warnings, $localFileExistsWarnings );
+		}
+
+		if ( $this->checkLocalFileWasDeleted( $localFile ) ) {
+			$warnings['was-deleted'] = $filename;
+		}
+
+		// If a file with the same name exists locally then the local file has already been tested
+		// for duplication of content
+		$ignoreLocalDupes = isset( $warnings[ 'exists '] );
+		$dupes = $this->checkAgainstExistingDupes( $hash, $ignoreLocalDupes );
+		if ( $dupes ) {
+			$warnings['duplicate'] = $dupes;
+		}
+
+		$archivedDupes = $this->checkAgainstArchiveDupes( $hash );
+		if ( $archivedDupes !== null ) {
+			$warnings['duplicate-archive'] = $archivedDupes;
+		}
+
+		return $warnings;
+	}
+
+	/**
+	 * Check whether the resulting filename is different from the desired one,
+	 * but ignore things like ucfirst() and spaces/underscore things
+	 *
+	 * @param string $filename
+	 * @param string $desiredFileName
+	 *
+	 * @return string|null String that was determined to be bad or null if the filename is okay
+	 */
+	private function checkBadFileName( $filename, $desiredFileName ) {
+		$comparableName = str_replace( ' ', '_', $desiredFileName );
+		$comparableName = Title::capitalize( $comparableName, NS_FILE );
+
+		if ( $desiredFileName != $filename && $comparableName != $filename ) {
+			return $filename;
+		}
+
+		return null;
+	}
+
+	/**
+	 * @param string $fileExtension The file extension to check
+	 *
+	 * @return array|null array with the following keys:
+	 *                    0 => string The final extension being used
+	 *                    1 => string[] The extensions that are allowed
+	 *                    2 => int The number of extensions that are allowed.
+	 */
+	private function checkUnwantedFileExtensions( $fileExtension ) {
+		global $wgCheckFileExtensions, $wgFileExtensions, $wgLang;
+
+		if ( $wgCheckFileExtensions ) {
+			$extensions = array_unique( $wgFileExtensions );
+			if ( !$this->checkFileExtension( $fileExtension, $extensions ) ) {
+				return [
+					$fileExtension,
+					$wgLang->commaList( $extensions ),
+					count( $extensions )
+				];
+			}
+		}
+
+		return null;
+	}
+
+	/**
+	 * @param int $fileSize
+	 *
+	 * @return array warnings
+	 */
+	private function checkFileSize( $fileSize ) {
+		global $wgUploadSizeWarning;
+
+		$warnings = [];
+
+		if ( $wgUploadSizeWarning && ( $fileSize > $wgUploadSizeWarning ) ) {
+			$warnings['large-file'] = [ $wgUploadSizeWarning, $fileSize ];
+		}
+
+		if ( $fileSize == 0 ) {
+			$warnings['empty-file'] = true;
+		}
+
+		return $warnings;
+	}
+
+	/**
+	 * @param LocalFile $localFile
+	 * @param string $hash sha1 hash of the file to check
+	 *
+	 * @return array warnings
+	 */
+	private function checkLocalFileExists( LocalFile $localFile, $hash ) {
+		$warnings = [];
+
+		$exists = self::getExistsWarning( $localFile );
+		if ( $exists !== false ) {
+			$warnings['exists'] = $exists;
+
+			// check if file is an exact duplicate of current file version
+			if ( $hash === $localFile->getSha1() ) {
+				$warnings['no-change'] = $localFile;
+			}
+
+			// check if file is an exact duplicate of older versions of this file
+			$history = $localFile->getHistory();
+			foreach ( $history as $oldFile ) {
+				if ( $hash === $oldFile->getSha1() ) {
+					$warnings['duplicate-version'][] = $oldFile;
+				}
+			}
+		}
+
+		return $warnings;
+	}
+
+	private function checkLocalFileWasDeleted( LocalFile $localFile ) {
+		return $localFile->wasDeleted() && !$localFile->exists();
+	}
+
+	/**
+	 * @param string $hash sha1 hash of the file to check
+	 * @param bool $ignoreLocalDupes True to ignore local duplicates
+	 *
+	 * @return File[] Duplicate files, if found.
+	 */
+	private function checkAgainstExistingDupes( $hash, $ignoreLocalDupes ) {
+		$dupes = RepoGroup::singleton()->findBySha1( $hash );
+		$title = $this->getTitle();
+		foreach ( $dupes as $key => $dupe ) {
+			if (
+				( $dupe instanceof LocalFile ) &&
+				$ignoreLocalDupes &&
+				$title->equals( $dupe->getTitle() )
+			) {
+				unset( $dupes[$key] );
+			}
+		}
+
+		return $dupes;
+	}
+
+	/**
+	 * @param string $hash sha1 hash of the file to check
+	 *
+	 * @return string|null Name of the dupe or empty string if discovered (depending on visibility)
+	 *                     null if the check discovered no dupes.
+	 */
+	private function checkAgainstArchiveDupes( $hash ) {
+		$archivedFile = new ArchivedFile( null, 0, '', $hash );
+		if ( $archivedFile->getID() > 0 ) {
+			if ( $archivedFile->userCan( File::DELETED_FILE ) ) {
+				return $archivedFile->getName();
+			} else {
+				return '';
+			}
+		}
+
+		return null;
+	}
+
+	/**
+	 * Really perform the upload. Stores the file in the local repo, watches
+	 * if necessary and runs the UploadComplete hook.
+	 *
+	 * @param string $comment
+	 * @param string $pageText
+	 * @param bool $watch Whether the file page should be added to user's watchlist.
+	 *   (This doesn't check $user's permissions.)
+	 * @param User $user
+	 * @param string[] $tags Change tags to add to the log entry and page revision.
+	 *   (This doesn't check $user's permissions.)
+	 * @return Status Indicating the whether the upload succeeded.
+	 */
+	public function performUpload( $comment, $pageText, $watch, $user, $tags = [] ) {
+		$this->getLocalFile()->load( File::READ_LATEST );
+		$props = $this->mFileProps;
+
+		$error = null;
+		Hooks::run( 'UploadVerifyUpload', [ $this, $user, $props, $comment, $pageText, &$error ] );
+		if ( $error ) {
+			if ( !is_array( $error ) ) {
+				$error = [ $error ];
+			}
+			return call_user_func_array( 'Status::newFatal', $error );
+		}
+
+		$status = $this->getLocalFile()->upload(
+			$this->mTempPath,
+			$comment,
+			$pageText,
+			File::DELETE_SOURCE,
+			$props,
+			false,
+			$user,
+			$tags
+		);
+
+		if ( $status->isGood() ) {
+			if ( $watch ) {
+				WatchAction::doWatch(
+					$this->getLocalFile()->getTitle(),
+					$user,
+					User::IGNORE_USER_RIGHTS
+				);
+			}
+			// Avoid PHP 7.1 warning of passing $this by reference
+			$uploadBase = $this;
+			Hooks::run( 'UploadComplete', [ &$uploadBase ] );
+
+			$this->postProcessUpload();
+		}
+
+		return $status;
+	}
+
+	/**
+	 * Perform extra steps after a successful upload.
+	 *
+	 * @since  1.25
+	 */
+	public function postProcessUpload() {
+	}
+
+	/**
+	 * Returns the title of the file to be uploaded. Sets mTitleError in case
+	 * the name was illegal.
+	 *
+	 * @return Title|null The title of the file or null in case the name was illegal
+	 */
+	public function getTitle() {
+		if ( $this->mTitle !== false ) {
+			return $this->mTitle;
+		}
+		if ( !is_string( $this->mDesiredDestName ) ) {
+			$this->mTitleError = self::ILLEGAL_FILENAME;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		}
+		/* Assume that if a user specified File:Something.jpg, this is an error
+		 * and that the namespace prefix needs to be stripped of.
+		 */
+		$title = Title::newFromText( $this->mDesiredDestName );
+		if ( $title && $title->getNamespace() == NS_FILE ) {
+			$this->mFilteredName = $title->getDBkey();
+		} else {
+			$this->mFilteredName = $this->mDesiredDestName;
+		}
+
+		# oi_archive_name is max 255 bytes, which include a timestamp and an
+		# exclamation mark, so restrict file name to 240 bytes.
+		if ( strlen( $this->mFilteredName ) > 240 ) {
+			$this->mTitleError = self::FILENAME_TOO_LONG;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		}
+
+		/**
+		 * Chop off any directories in the given filename. Then
+		 * filter out illegal characters, and try to make a legible name
+		 * out of it. We'll strip some silently that Title would die on.
+		 */
+		$this->mFilteredName = wfStripIllegalFilenameChars( $this->mFilteredName );
+		/* Normalize to title form before we do any further processing */
+		$nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
+		if ( is_null( $nt ) ) {
+			$this->mTitleError = self::ILLEGAL_FILENAME;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		}
+		$this->mFilteredName = $nt->getDBkey();
+
+		/**
+		 * We'll want to blacklist against *any* 'extension', and use
+		 * only the final one for the whitelist.
+		 */
+		list( $partname, $ext ) = $this->splitExtensions( $this->mFilteredName );
+
+		if ( count( $ext ) ) {
+			$this->mFinalExtension = trim( $ext[count( $ext ) - 1] );
+		} else {
+			$this->mFinalExtension = '';
+
+			# No extension, try guessing one
+			$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
+			$mime = $magic->guessMimeType( $this->mTempPath );
+			if ( $mime !== 'unknown/unknown' ) {
+				# Get a space separated list of extensions
+				$extList = $magic->getExtensionsForType( $mime );
+				if ( $extList ) {
+					# Set the extension to the canonical extension
+					$this->mFinalExtension = strtok( $extList, ' ' );
+
+					# Fix up the other variables
+					$this->mFilteredName .= ".{$this->mFinalExtension}";
+					$nt = Title::makeTitleSafe( NS_FILE, $this->mFilteredName );
+					$ext = [ $this->mFinalExtension ];
+				}
+			}
+		}
+
+		/* Don't allow users to override the blacklist (check file extension) */
+		global $wgCheckFileExtensions, $wgStrictFileExtensions;
+		global $wgFileExtensions, $wgFileBlacklist;
+
+		$blackListedExtensions = $this->checkFileExtensionList( $ext, $wgFileBlacklist );
+
+		if ( $this->mFinalExtension == '' ) {
+			$this->mTitleError = self::FILETYPE_MISSING;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		} elseif ( $blackListedExtensions ||
+			( $wgCheckFileExtensions && $wgStrictFileExtensions &&
+				!$this->checkFileExtension( $this->mFinalExtension, $wgFileExtensions ) )
+		) {
+			$this->mBlackListedExtensions = $blackListedExtensions;
+			$this->mTitleError = self::FILETYPE_BADTYPE;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		}
+
+		// Windows may be broken with special characters, see T3780
+		if ( !preg_match( '/^[\x0-\x7f]*$/', $nt->getText() )
+			&& !RepoGroup::singleton()->getLocalRepo()->backendSupportsUnicodePaths()
+		) {
+			$this->mTitleError = self::WINDOWS_NONASCII_FILENAME;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		}
+
+		# If there was more than one "extension", reassemble the base
+		# filename to prevent bogus complaints about length
+		if ( count( $ext ) > 1 ) {
+			$iterations = count( $ext ) - 1;
+			for ( $i = 0; $i < $iterations; $i++ ) {
+				$partname .= '.' . $ext[$i];
+			}
+		}
+
+		if ( strlen( $partname ) < 1 ) {
+			$this->mTitleError = self::MIN_LENGTH_PARTNAME;
+			$this->mTitle = null;
+
+			return $this->mTitle;
+		}
+
+		$this->mTitle = $nt;
+
+		return $this->mTitle;
+	}
+
+	/**
+	 * Return the local file and initializes if necessary.
+	 *
+	 * @return LocalFile|null
+	 */
+	public function getLocalFile() {
+		if ( is_null( $this->mLocalFile ) ) {
+			$nt = $this->getTitle();
+			$this->mLocalFile = is_null( $nt ) ? null : wfLocalFile( $nt );
+		}
+
+		return $this->mLocalFile;
+	}
+
+	/**
+	 * @return UploadStashFile|null
+	 */
+	public function getStashFile() {
+		return $this->mStashFile;
+	}
+
+	/**
+	 * Like stashFile(), but respects extensions' wishes to prevent the stashing. verifyUpload() must
+	 * be called before calling this method (unless $isPartial is true).
+	 *
+	 * Upload stash exceptions are also caught and converted to an error status.
+	 *
+	 * @since 1.28
+	 * @param User $user
+	 * @param bool $isPartial Pass `true` if this is a part of a chunked upload (not a complete file).
+	 * @return Status If successful, value is an UploadStashFile instance
+	 */
+	public function tryStashFile( User $user, $isPartial = false ) {
+		if ( !$isPartial ) {
+			$error = $this->runUploadStashFileHook( $user );
+			if ( $error ) {
+				return call_user_func_array( 'Status::newFatal', $error );
+			}
+		}
+		try {
+			$file = $this->doStashFile( $user );
+			return Status::newGood( $file );
+		} catch ( UploadStashException $e ) {
+			return Status::newFatal( 'uploadstash-exception', get_class( $e ), $e->getMessage() );
+		}
+	}
+
+	/**
+	 * @param User $user
+	 * @return array|null Error message and parameters, null if there's no error
+	 */
+	protected function runUploadStashFileHook( User $user ) {
+		$props = $this->mFileProps;
+		$error = null;
+		Hooks::run( 'UploadStashFile', [ $this, $user, $props, &$error ] );
+		if ( $error ) {
+			if ( !is_array( $error ) ) {
+				$error = [ $error ];
+			}
+		}
+		return $error;
+	}
+
+	/**
+	 * If the user does not supply all necessary information in the first upload
+	 * form submission (either by accident or by design) then we may want to
+	 * stash the file temporarily, get more information, and publish the file
+	 * later.
+	 *
+	 * This method will stash a file in a temporary directory for later
+	 * processing, and save the necessary descriptive info into the database.
+	 * This method returns the file object, which also has a 'fileKey' property
+	 * which can be passed through a form or API request to find this stashed
+	 * file again.
+	 *
+	 * @deprecated since 1.28 Use tryStashFile() instead
+	 * @param User $user
+	 * @return UploadStashFile Stashed file
+	 * @throws UploadStashBadPathException
+	 * @throws UploadStashFileException
+	 * @throws UploadStashNotLoggedInException
+	 */
+	public function stashFile( User $user = null ) {
+		return $this->doStashFile( $user );
+	}
+
+	/**
+	 * Implementation for stashFile() and tryStashFile().
+	 *
+	 * @param User $user
+	 * @return UploadStashFile Stashed file
+	 */
+	protected function doStashFile( User $user = null ) {
+		$stash = RepoGroup::singleton()->getLocalRepo()->getUploadStash( $user );
+		$file = $stash->stashFile( $this->mTempPath, $this->getSourceType() );
+		$this->mStashFile = $file;
+
+		return $file;
+	}
+
+	/**
+	 * Stash a file in a temporary directory, returning a key which can be used
+	 * to find the file again. See stashFile().
+	 *
+	 * @deprecated since 1.28
+	 * @return string File key
+	 */
+	public function stashFileGetKey() {
+		wfDeprecated( __METHOD__, '1.28' );
+		return $this->doStashFile()->getFileKey();
+	}
+
+	/**
+	 * alias for stashFileGetKey, for backwards compatibility
+	 *
+	 * @deprecated since 1.28
+	 * @return string File key
+	 */
+	public function stashSession() {
+		wfDeprecated( __METHOD__, '1.28' );
+		return $this->doStashFile()->getFileKey();
+	}
+
+	/**
+	 * If we've modified the upload file we need to manually remove it
+	 * on exit to clean up.
+	 */
+	public function cleanupTempFile() {
+		if ( $this->mRemoveTempFile && $this->tempFileObj ) {
+			// Delete when all relevant TempFSFile handles go out of scope
+			wfDebug( __METHOD__ . ": Marked temporary file '{$this->mTempPath}' for removal\n" );
+			$this->tempFileObj->autocollect();
+		}
+	}
+
+	public function getTempPath() {
+		return $this->mTempPath;
+	}
+
+	/**
+	 * Split a file into a base name and all dot-delimited 'extensions'
+	 * on the end. Some web server configurations will fall back to
+	 * earlier pseudo-'extensions' to determine type and execute
+	 * scripts, so the blacklist needs to check them all.
+	 *
+	 * @param string $filename
+	 * @return array
+	 */
+	public static function splitExtensions( $filename ) {
+		$bits = explode( '.', $filename );
+		$basename = array_shift( $bits );
+
+		return [ $basename, $bits ];
+	}
+
+	/**
+	 * Perform case-insensitive match against a list of file extensions.
+	 * Returns true if the extension is in the list.
+	 *
+	 * @param string $ext
+	 * @param array $list
+	 * @return bool
+	 */
+	public static function checkFileExtension( $ext, $list ) {
+		return in_array( strtolower( $ext ), $list );
+	}
+
+	/**
+	 * Perform case-insensitive match against a list of file extensions.
+	 * Returns an array of matching extensions.
+	 *
+	 * @param array $ext
+	 * @param array $list
+	 * @return bool
+	 */
+	public static function checkFileExtensionList( $ext, $list ) {
+		return array_intersect( array_map( 'strtolower', $ext ), $list );
+	}
+
+	/**
+	 * Checks if the MIME type of the uploaded file matches the file extension.
+	 *
+	 * @param string $mime The MIME type of the uploaded file
+	 * @param string $extension The filename extension that the file is to be served with
+	 * @return bool
+	 */
+	public static function verifyExtension( $mime, $extension ) {
+		$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
+
+		if ( !$mime || $mime == 'unknown' || $mime == 'unknown/unknown' ) {
+			if ( !$magic->isRecognizableExtension( $extension ) ) {
+				wfDebug( __METHOD__ . ": passing file with unknown detected mime type; " .
+					"unrecognized extension '$extension', can't verify\n" );
+
+				return true;
+			} else {
+				wfDebug( __METHOD__ . ": rejecting file with unknown detected mime type; " .
+					"recognized extension '$extension', so probably invalid file\n" );
+
+				return false;
+			}
+		}
+
+		$match = $magic->isMatchingExtension( $extension, $mime );
+
+		if ( $match === null ) {
+			if ( $magic->getTypesForExtension( $extension ) !== null ) {
+				wfDebug( __METHOD__ . ": No extension known for $mime, but we know a mime for $extension\n" );
+
+				return false;
+			} else {
+				wfDebug( __METHOD__ . ": no file extension known for mime type $mime, passing file\n" );
+
+				return true;
+			}
+		} elseif ( $match === true ) {
+			wfDebug( __METHOD__ . ": mime type $mime matches extension $extension, passing file\n" );
+
+			/** @todo If it's a bitmap, make sure PHP or ImageMagick resp. can handle it! */
+			return true;
+		} else {
+			wfDebug( __METHOD__
+				. ": mime type $mime mismatches file extension $extension, rejecting file\n" );
+
+			return false;
+		}
+	}
+
+	/**
+	 * Heuristic for detecting files that *could* contain JavaScript instructions or
+	 * things that may look like HTML to a browser and are thus
+	 * potentially harmful. The present implementation will produce false
+	 * positives in some situations.
+	 *
+	 * @param string $file Pathname to the temporary upload file
+	 * @param string $mime The MIME type of the file
+	 * @param string $extension The extension of the file
+	 * @return bool True if the file contains something looking like embedded scripts
+	 */
+	public static function detectScript( $file, $mime, $extension ) {
+		global $wgAllowTitlesInSVG;
+
+		# ugly hack: for text files, always look at the entire file.
+		# For binary field, just check the first K.
+
+		if ( strpos( $mime, 'text/' ) === 0 ) {
+			$chunk = file_get_contents( $file );
+		} else {
+			$fp = fopen( $file, 'rb' );
+			$chunk = fread( $fp, 1024 );
+			fclose( $fp );
+		}
+
+		$chunk = strtolower( $chunk );
+
+		if ( !$chunk ) {
+			return false;
+		}
+
+		# decode from UTF-16 if needed (could be used for obfuscation).
+		if ( substr( $chunk, 0, 2 ) == "\xfe\xff" ) {
+			$enc = 'UTF-16BE';
+		} elseif ( substr( $chunk, 0, 2 ) == "\xff\xfe" ) {
+			$enc = 'UTF-16LE';
+		} else {
+			$enc = null;
+		}
+
+		if ( $enc ) {
+			$chunk = iconv( $enc, "ASCII//IGNORE", $chunk );
+		}
+
+		$chunk = trim( $chunk );
+
+		/** @todo FIXME: Convert from UTF-16 if necessary! */
+		wfDebug( __METHOD__ . ": checking for embedded scripts and HTML stuff\n" );
+
+		# check for HTML doctype
+		if ( preg_match( "/<!DOCTYPE *X?HTML/i", $chunk ) ) {
+			return true;
+		}
+
+		// Some browsers will interpret obscure xml encodings as UTF-8, while
+		// PHP/expat will interpret the given encoding in the xml declaration (T49304)
+		if ( $extension == 'svg' || strpos( $mime, 'image/svg' ) === 0 ) {
+			if ( self::checkXMLEncodingMissmatch( $file ) ) {
+				return true;
+			}
+		}
+
+		/**
+		 * Internet Explorer for Windows performs some really stupid file type
+		 * autodetection which can cause it to interpret valid image files as HTML
+		 * and potentially execute JavaScript, creating a cross-site scripting
+		 * attack vectors.
+		 *
+		 * Apple's Safari browser also performs some unsafe file type autodetection
+		 * which can cause legitimate files to be interpreted as HTML if the
+		 * web server is not correctly configured to send the right content-type
+		 * (or if you're really uploading plain text and octet streams!)
+		 *
+		 * Returns true if IE is likely to mistake the given file for HTML.
+		 * Also returns true if Safari would mistake the given file for HTML
+		 * when served with a generic content-type.
+		 */
+		$tags = [
+			'<a href',
+			'<body',
+			'<head',
+			'<html', # also in safari
+			'<img',
+			'<pre',
+			'<script', # also in safari
+			'<table'
+		];
+
+		if ( !$wgAllowTitlesInSVG && $extension !== 'svg' && $mime !== 'image/svg' ) {
+			$tags[] = '<title';
+		}
+
+		foreach ( $tags as $tag ) {
+			if ( false !== strpos( $chunk, $tag ) ) {
+				wfDebug( __METHOD__ . ": found something that may make it be mistaken for html: $tag\n" );
+
+				return true;
+			}
+		}
+
+		/*
+		 * look for JavaScript
+		 */
+
+		# resolve entity-refs to look at attributes. may be harsh on big files... cache result?
+		$chunk = Sanitizer::decodeCharReferences( $chunk );
+
+		# look for script-types
+		if ( preg_match( '!type\s*=\s*[\'"]?\s*(?:\w*/)?(?:ecma|java)!sim', $chunk ) ) {
+			wfDebug( __METHOD__ . ": found script types\n" );
+
+			return true;
+		}
+
+		# look for html-style script-urls
+		if ( preg_match( '!(?:href|src|data)\s*=\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
+			wfDebug( __METHOD__ . ": found html-style script urls\n" );
+
+			return true;
+		}
+
+		# look for css-style script-urls
+		if ( preg_match( '!url\s*\(\s*[\'"]?\s*(?:ecma|java)script:!sim', $chunk ) ) {
+			wfDebug( __METHOD__ . ": found css-style script urls\n" );
+
+			return true;
+		}
+
+		wfDebug( __METHOD__ . ": no scripts found\n" );
+
+		return false;
+	}
+
+	/**
+	 * Check a whitelist of xml encodings that are known not to be interpreted differently
+	 * by the server's xml parser (expat) and some common browsers.
+	 *
+	 * @param string $file Pathname to the temporary upload file
+	 * @return bool True if the file contains an encoding that could be misinterpreted
+	 */
+	public static function checkXMLEncodingMissmatch( $file ) {
+		global $wgSVGMetadataCutoff;
+		$contents = file_get_contents( $file, false, null, 0, $wgSVGMetadataCutoff );
+		$encodingRegex = '!encoding[ \t\n\r]*=[ \t\n\r]*[\'"](.*?)[\'"]!si';
+
+		if ( preg_match( "!<\?xml\b(.*?)\?>!si", $contents, $matches ) ) {
+			if ( preg_match( $encodingRegex, $matches[1], $encMatch )
+				&& !in_array( strtoupper( $encMatch[1] ), self::$safeXmlEncodings )
+			) {
+				wfDebug( __METHOD__ . ": Found unsafe XML encoding '{$encMatch[1]}'\n" );
+
+				return true;
+			}
+		} elseif ( preg_match( "!<\?xml\b!si", $contents ) ) {
+			// Start of XML declaration without an end in the first $wgSVGMetadataCutoff
+			// bytes. There shouldn't be a legitimate reason for this to happen.
+			wfDebug( __METHOD__ . ": Unmatched XML declaration start\n" );
+
+			return true;
+		} elseif ( substr( $contents, 0, 4 ) == "\x4C\x6F\xA7\x94" ) {
+			// EBCDIC encoded XML
+			wfDebug( __METHOD__ . ": EBCDIC Encoded XML\n" );
+
+			return true;
+		}
+
+		// It's possible the file is encoded with multi-byte encoding, so re-encode attempt to
+		// detect the encoding in case is specifies an encoding not whitelisted in self::$safeXmlEncodings
+		$attemptEncodings = [ 'UTF-16', 'UTF-16BE', 'UTF-32', 'UTF-32BE' ];
+		foreach ( $attemptEncodings as $encoding ) {
+			Wikimedia\suppressWarnings();
+			$str = iconv( $encoding, 'UTF-8', $contents );
+			Wikimedia\restoreWarnings();
+			if ( $str != '' && preg_match( "!<\?xml\b(.*?)\?>!si", $str, $matches ) ) {
+				if ( preg_match( $encodingRegex, $matches[1], $encMatch )
+					&& !in_array( strtoupper( $encMatch[1] ), self::$safeXmlEncodings )
+				) {
+					wfDebug( __METHOD__ . ": Found unsafe XML encoding '{$encMatch[1]}'\n" );
+
+					return true;
+				}
+			} elseif ( $str != '' && preg_match( "!<\?xml\b!si", $str ) ) {
+				// Start of XML declaration without an end in the first $wgSVGMetadataCutoff
+				// bytes. There shouldn't be a legitimate reason for this to happen.
+				wfDebug( __METHOD__ . ": Unmatched XML declaration start\n" );
+
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * @param string $filename
+	 * @param bool $partial
+	 * @return mixed False of the file is verified (does not contain scripts), array otherwise.
+	 */
+	protected function detectScriptInSvg( $filename, $partial ) {
+		$this->mSVGNSError = false;
+		$check = new XmlTypeCheck(
+			$filename,
+			[ $this, 'checkSvgScriptCallback' ],
+			true,
+			[
+				'processing_instruction_handler' => 'UploadBase::checkSvgPICallback',
+				'external_dtd_handler' => 'UploadBase::checkSvgExternalDTD',
+			]
+		);
+		if ( $check->wellFormed !== true ) {
+			// Invalid xml (T60553)
+			// But only when non-partial (T67724)
+			return $partial ? false : [ 'uploadinvalidxml' ];
+		} elseif ( $check->filterMatch ) {
+			if ( $this->mSVGNSError ) {
+				return [ 'uploadscriptednamespace', $this->mSVGNSError ];
+			}
+
+			return $check->filterMatchType;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Callback to filter SVG Processing Instructions.
+	 * @param string $target Processing instruction name
+	 * @param string $data Processing instruction attribute and value
+	 * @return bool (true if the filter identified something bad)
+	 */
+	public static function checkSvgPICallback( $target, $data ) {
+		// Don't allow external stylesheets (T59550)
+		if ( preg_match( '/xml-stylesheet/i', $target ) ) {
+			return [ 'upload-scripted-pi-callback' ];
+		}
+
+		return false;
+	}
+
+	/**
+	 * Verify that DTD urls referenced are only the standard dtds
+	 *
+	 * Browsers seem to ignore external dtds. However just to be on the
+	 * safe side, only allow dtds from the svg standard.
+	 *
+	 * @param string $type PUBLIC or SYSTEM
+	 * @param string $publicId The well-known public identifier for the dtd
+	 * @param string $systemId The url for the external dtd
+	 * @return bool|array
+	 */
+	public static function checkSvgExternalDTD( $type, $publicId, $systemId ) {
+		// This doesn't include the XHTML+MathML+SVG doctype since we don't
+		// allow XHTML anyways.
+		$allowedDTDs = [
+			'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd',
+			'http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd',
+			'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-basic.dtd',
+			'http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-tiny.dtd',
+			// https://phabricator.wikimedia.org/T168856
+			'http://www.w3.org/TR/2001/PR-SVG-20010719/DTD/svg10.dtd',
+		];
+		if ( $type !== 'PUBLIC'
+			|| !in_array( $systemId, $allowedDTDs )
+			|| strpos( $publicId, "-//W3C//" ) !== 0
+		) {
+			return [ 'upload-scripted-dtd' ];
+		}
+		return false;
+	}
+
+	/**
+	 * @todo Replace this with a whitelist filter!
+	 * @param string $element
+	 * @param array $attribs
+	 * @param array $data
+	 * @return bool
+	 */
+	public function checkSvgScriptCallback( $element, $attribs, $data = null ) {
+		list( $namespace, $strippedElement ) = $this->splitXmlNamespace( $element );
+
+		// We specifically don't include:
+		// http://www.w3.org/1999/xhtml (T62771)
+		static $validNamespaces = [
+			'',
+			'adobe:ns:meta/',
+			'http://creativecommons.org/ns#',
+			'http://inkscape.sourceforge.net/dtd/sodipodi-0.dtd',
+			'http://ns.adobe.com/adobeillustrator/10.0/',
+			'http://ns.adobe.com/adobesvgviewerextensions/3.0/',
+			'http://ns.adobe.com/extensibility/1.0/',
+			'http://ns.adobe.com/flows/1.0/',
+			'http://ns.adobe.com/illustrator/1.0/',
+			'http://ns.adobe.com/imagereplacement/1.0/',
+			'http://ns.adobe.com/pdf/1.3/',
+			'http://ns.adobe.com/photoshop/1.0/',
+			'http://ns.adobe.com/saveforweb/1.0/',
+			'http://ns.adobe.com/variables/1.0/',
+			'http://ns.adobe.com/xap/1.0/',
+			'http://ns.adobe.com/xap/1.0/g/',
+			'http://ns.adobe.com/xap/1.0/g/img/',
+			'http://ns.adobe.com/xap/1.0/mm/',
+			'http://ns.adobe.com/xap/1.0/rights/',
+			'http://ns.adobe.com/xap/1.0/stype/dimensions#',
+			'http://ns.adobe.com/xap/1.0/stype/font#',
+			'http://ns.adobe.com/xap/1.0/stype/manifestitem#',
+			'http://ns.adobe.com/xap/1.0/stype/resourceevent#',
+			'http://ns.adobe.com/xap/1.0/stype/resourceref#',
+			'http://ns.adobe.com/xap/1.0/t/pg/',
+			'http://purl.org/dc/elements/1.1/',
+			'http://purl.org/dc/elements/1.1',
+			'http://schemas.microsoft.com/visio/2003/svgextensions/',
+			'http://sodipodi.sourceforge.net/dtd/sodipodi-0.dtd',
+			'http://taptrix.com/inkpad/svg_extensions',
+			'http://web.resource.org/cc/',
+			'http://www.freesoftware.fsf.org/bkchem/cdml',
+			'http://www.inkscape.org/namespaces/inkscape',
+			'http://www.opengis.net/gml',
+			'http://www.w3.org/1999/02/22-rdf-syntax-ns#',
+			'http://www.w3.org/2000/svg',
+			'http://www.w3.org/tr/rec-rdf-syntax/',
+			'http://www.w3.org/2000/01/rdf-schema#',
+		];
+
+		// Inkscape mangles namespace definitions created by Adobe Illustrator.
+		// This is nasty but harmless. (T144827)
+		$isBuggyInkscape = preg_match( '/^&(#38;)*ns_[a-z_]+;$/', $namespace );
+
+		if ( !( $isBuggyInkscape || in_array( $namespace, $validNamespaces ) ) ) {
+			wfDebug( __METHOD__ . ": Non-svg namespace '$namespace' in uploaded file.\n" );
+			/** @todo Return a status object to a closure in XmlTypeCheck, for MW1.21+ */
+			$this->mSVGNSError = $namespace;
+
+			return true;
+		}
+
+		/*
+		 * check for elements that can contain javascript
+		 */
+		if ( $strippedElement == 'script' ) {
+			wfDebug( __METHOD__ . ": Found script element '$element' in uploaded file.\n" );
+
+			return [ 'uploaded-script-svg', $strippedElement ];
+		}
+
+		# e.g., <svg xmlns="http://www.w3.org/2000/svg">
+		#  <handler xmlns:ev="http://www.w3.org/2001/xml-events" ev:event="load">alert(1)</handler> </svg>
+		if ( $strippedElement == 'handler' ) {
+			wfDebug( __METHOD__ . ": Found scriptable element '$element' in uploaded file.\n" );
+
+			return [ 'uploaded-script-svg', $strippedElement ];
+		}
+
+		# SVG reported in Feb '12 that used xml:stylesheet to generate javascript block
+		if ( $strippedElement == 'stylesheet' ) {
+			wfDebug( __METHOD__ . ": Found scriptable element '$element' in uploaded file.\n" );
+
+			return [ 'uploaded-script-svg', $strippedElement ];
+		}
+
+		# Block iframes, in case they pass the namespace check
+		if ( $strippedElement == 'iframe' ) {
+			wfDebug( __METHOD__ . ": iframe in uploaded file.\n" );
+
+			return [ 'uploaded-script-svg', $strippedElement ];
+		}
+
+		# Check <style> css
+		if ( $strippedElement == 'style'
+			&& self::checkCssFragment( Sanitizer::normalizeCss( $data ) )
+		) {
+			wfDebug( __METHOD__ . ": hostile css in style element.\n" );
+			return [ 'uploaded-hostile-svg' ];
+		}
+
+		foreach ( $attribs as $attrib => $value ) {
+			$stripped = $this->stripXmlNamespace( $attrib );
+			$value = strtolower( $value );
+
+			if ( substr( $stripped, 0, 2 ) == 'on' ) {
+				wfDebug( __METHOD__
+					. ": Found event-handler attribute '$attrib'='$value' in uploaded file.\n" );
+
+				return [ 'uploaded-event-handler-on-svg', $attrib, $value ];
+			}
+
+			# Do not allow relative links, or unsafe url schemas.
+			# For <a> tags, only data:, http: and https: and same-document
+			# fragment links are allowed. For all other tags, only data:
+			# and fragment are allowed.
+			if ( $stripped == 'href'
+				&& $value !== ''
+				&& strpos( $value, 'data:' ) !== 0
+				&& strpos( $value, '#' ) !== 0
+			) {
+				if ( !( $strippedElement === 'a'
+					&& preg_match( '!^https?://!i', $value ) )
+				) {
+					wfDebug( __METHOD__ . ": Found href attribute <$strippedElement "
+						. "'$attrib'='$value' in uploaded file.\n" );
+
+					return [ 'uploaded-href-attribute-svg', $strippedElement, $attrib, $value ];
+				}
+			}
+
+			# only allow data: targets that should be safe. This prevents vectors like,
+			# image/svg, text/xml, application/xml, and text/html, which can contain scripts
+			if ( $stripped == 'href' && strncasecmp( 'data:', $value, 5 ) === 0 ) {
+				// rfc2397 parameters. This is only slightly slower than (;[\w;]+)*.
+				// phpcs:ignore Generic.Files.LineLength
+				$parameters = '(?>;[a-zA-Z0-9\!#$&\'*+.^_`{|}~-]+=(?>[a-zA-Z0-9\!#$&\'*+.^_`{|}~-]+|"(?>[\0-\x0c\x0e-\x21\x23-\x5b\x5d-\x7f]+|\\\\[\0-\x7f])*"))*(?:;base64)?';
+
+				if ( !preg_match( "!^data:\s*image/(gif|jpeg|jpg|png)$parameters,!i", $value ) ) {
+					wfDebug( __METHOD__ . ": Found href to unwhitelisted data: uri "
+						. "\"<$strippedElement '$attrib'='$value'...\" in uploaded file.\n" );
+					return [ 'uploaded-href-unsafe-target-svg', $strippedElement, $attrib, $value ];
+				}
+			}
+
+			# Change href with animate from (http://html5sec.org/#137).
+			if ( $stripped === 'attributename'
+				&& $strippedElement === 'animate'
+				&& $this->stripXmlNamespace( $value ) == 'href'
+			) {
+				wfDebug( __METHOD__ . ": Found animate that might be changing href using from "
+					. "\"<$strippedElement '$attrib'='$value'...\" in uploaded file.\n" );
+
+				return [ 'uploaded-animate-svg', $strippedElement, $attrib, $value ];
+			}
+
+			# use set/animate to add event-handler attribute to parent
+			if ( ( $strippedElement == 'set' || $strippedElement == 'animate' )
+				&& $stripped == 'attributename'
+				&& substr( $value, 0, 2 ) == 'on'
+			) {
+				wfDebug( __METHOD__ . ": Found svg setting event-handler attribute with "
+					. "\"<$strippedElement $stripped='$value'...\" in uploaded file.\n" );
+
+				return [ 'uploaded-setting-event-handler-svg', $strippedElement, $stripped, $value ];
+			}
+
+			# use set to add href attribute to parent element
+			if ( $strippedElement == 'set'
+				&& $stripped == 'attributename'
+				&& strpos( $value, 'href' ) !== false
+			) {
+				wfDebug( __METHOD__ . ": Found svg setting href attribute '$value' in uploaded file.\n" );
+
+				return [ 'uploaded-setting-href-svg' ];
+			}
+
+			# use set to add a remote / data / script target to an element
+			if ( $strippedElement == 'set'
+				&& $stripped == 'to'
+				&& preg_match( '!(http|https|data|script):!sim', $value )
+			) {
+				wfDebug( __METHOD__ . ": Found svg setting attribute to '$value' in uploaded file.\n" );
+
+				return [ 'uploaded-wrong-setting-svg', $value ];
+			}
+
+			# use handler attribute with remote / data / script
+			if ( $stripped == 'handler' && preg_match( '!(http|https|data|script):!sim', $value ) ) {
+				wfDebug( __METHOD__ . ": Found svg setting handler with remote/data/script "
+					. "'$attrib'='$value' in uploaded file.\n" );
+
+				return [ 'uploaded-setting-handler-svg', $attrib, $value ];
+			}
+
+			# use CSS styles to bring in remote code
+			if ( $stripped == 'style'
+				&& self::checkCssFragment( Sanitizer::normalizeCss( $value ) )
+			) {
+				wfDebug( __METHOD__ . ": Found svg setting a style with "
+					. "remote url '$attrib'='$value' in uploaded file.\n" );
+				return [ 'uploaded-remote-url-svg', $attrib, $value ];
+			}
+
+			# Several attributes can include css, css character escaping isn't allowed
+			$cssAttrs = [ 'font', 'clip-path', 'fill', 'filter', 'marker',
+				'marker-end', 'marker-mid', 'marker-start', 'mask', 'stroke' ];
+			if ( in_array( $stripped, $cssAttrs )
+				&& self::checkCssFragment( $value )
+			) {
+				wfDebug( __METHOD__ . ": Found svg setting a style with "
+					. "remote url '$attrib'='$value' in uploaded file.\n" );
+				return [ 'uploaded-remote-url-svg', $attrib, $value ];
+			}
+
+			# image filters can pull in url, which could be svg that executes scripts
+			if ( $strippedElement == 'image'
+				&& $stripped == 'filter'
+				&& preg_match( '!url\s*\(!sim', $value )
+			) {
+				wfDebug( __METHOD__ . ": Found image filter with url: "
+					. "\"<$strippedElement $stripped='$value'...\" in uploaded file.\n" );
+
+				return [ 'uploaded-image-filter-svg', $strippedElement, $stripped, $value ];
+			}
+		}
+
+		return false; // No scripts detected
+	}
+
+	/**
+	 * Check a block of CSS or CSS fragment for anything that looks like
+	 * it is bringing in remote code.
+	 * @param string $value a string of CSS
+	 * @param bool $propOnly only check css properties (start regex with :)
+	 * @return bool true if the CSS contains an illegal string, false if otherwise
+	 */
+	private static function checkCssFragment( $value ) {
+		# Forbid external stylesheets, for both reliability and to protect viewer's privacy
+		if ( stripos( $value, '@import' ) !== false ) {
+			return true;
+		}
+
+		# We allow @font-face to embed fonts with data: urls, so we snip the string
+		# 'url' out so this case won't match when we check for urls below
+		$pattern = '!(@font-face\s*{[^}]*src:)url(\("data:;base64,)!im';
+		$value = preg_replace( $pattern, '$1$2', $value );
+
+		# Check for remote and executable CSS. Unlike in Sanitizer::checkCss, the CSS
+		# properties filter and accelerator don't seem to be useful for xss in SVG files.
+		# Expression and -o-link don't seem to work either, but filtering them here in case.
+		# Additionally, we catch remote urls like url("http:..., url('http:..., url(http:...,
+		# but not local ones such as url("#..., url('#..., url(#....
+		if ( preg_match( '!expression
+				| -o-link\s*:
+				| -o-link-source\s*:
+				| -o-replace\s*:!imx', $value ) ) {
+			return true;
+		}
+
+		if ( preg_match_all(
+				"!(\s*(url|image|image-set)\s*\(\s*[\"']?\s*[^#]+.*?\))!sim",
+				$value,
+				$matches
+			) !== 0
+		) {
+			# TODO: redo this in one regex. Until then, url("#whatever") matches the first
+			foreach ( $matches[1] as $match ) {
+				if ( !preg_match( "!\s*(url|image|image-set)\s*\(\s*(#|'#|\"#)!im", $match ) ) {
+					return true;
+				}
+			}
+		}
+
+		if ( preg_match( '/[\000-\010\013\016-\037\177]/', $value ) ) {
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Divide the element name passed by the xml parser to the callback into URI and prifix.
+	 * @param string $element
+	 * @return array Containing the namespace URI and prefix
+	 */
+	private static function splitXmlNamespace( $element ) {
+		// 'http://www.w3.org/2000/svg:script' -> [ 'http://www.w3.org/2000/svg', 'script' ]
+		$parts = explode( ':', strtolower( $element ) );
+		$name = array_pop( $parts );
+		$ns = implode( ':', $parts );
+
+		return [ $ns, $name ];
+	}
+
+	/**
+	 * @param string $name
+	 * @return string
+	 */
+	private function stripXmlNamespace( $name ) {
+		// 'http://www.w3.org/2000/svg:script' -> 'script'
+		$parts = explode( ':', strtolower( $name ) );
+
+		return array_pop( $parts );
+	}
+
+	/**
+	 * Generic wrapper function for a virus scanner program.
+	 * This relies on the $wgAntivirus and $wgAntivirusSetup variables.
+	 * $wgAntivirusRequired may be used to deny upload if the scan fails.
+	 *
+	 * @param string $file Pathname to the temporary upload file
+	 * @return mixed False if not virus is found, null if the scan fails or is disabled,
+	 *   or a string containing feedback from the virus scanner if a virus was found.
+	 *   If textual feedback is missing but a virus was found, this function returns true.
+	 */
+	public static function detectVirus( $file ) {
+		global $wgAntivirus, $wgAntivirusSetup, $wgAntivirusRequired, $wgOut;
+
+		if ( !$wgAntivirus ) {
+			wfDebug( __METHOD__ . ": virus scanner disabled\n" );
+
+			return null;
+		}
+
+		if ( !$wgAntivirusSetup[$wgAntivirus] ) {
+			wfDebug( __METHOD__ . ": unknown virus scanner: $wgAntivirus\n" );
+			$wgOut->wrapWikiMsg( "<div class=\"error\">\n$1\n</div>",
+				[ 'virus-badscanner', $wgAntivirus ] );
+
+			return wfMessage( 'virus-unknownscanner' )->text() . " $wgAntivirus";
+		}
+
+		# look up scanner configuration
+		$command = $wgAntivirusSetup[$wgAntivirus]['command'];
+		$exitCodeMap = $wgAntivirusSetup[$wgAntivirus]['codemap'];
+		$msgPattern = isset( $wgAntivirusSetup[$wgAntivirus]['messagepattern'] ) ?
+			$wgAntivirusSetup[$wgAntivirus]['messagepattern'] : null;
+
+		if ( strpos( $command, "%f" ) === false ) {
+			# simple pattern: append file to scan
+			$command .= " " . wfEscapeShellArg( $file );
+		} else {
+			# complex pattern: replace "%f" with file to scan
+			$command = str_replace( "%f", wfEscapeShellArg( $file ), $command );
+		}
+
+		wfDebug( __METHOD__ . ": running virus scan: $command \n" );
+
+		# execute virus scanner
+		$exitCode = false;
+
+		# NOTE: there's a 50 line workaround to make stderr redirection work on windows, too.
+		#      that does not seem to be worth the pain.
+		#      Ask me (Duesentrieb) about it if it's ever needed.
+		$output = wfShellExecWithStderr( $command, $exitCode );
+
+		# map exit code to AV_xxx constants.
+		$mappedCode = $exitCode;
+		if ( $exitCodeMap ) {
+			if ( isset( $exitCodeMap[$exitCode] ) ) {
+				$mappedCode = $exitCodeMap[$exitCode];
+			} elseif ( isset( $exitCodeMap["*"] ) ) {
+				$mappedCode = $exitCodeMap["*"];
+			}
+		}
+
+		/* NB: AV_NO_VIRUS is 0 but AV_SCAN_FAILED is false,
+		 * so we need the strict equalities === and thus can't use a switch here
+		 */
+		if ( $mappedCode === AV_SCAN_FAILED ) {
+			# scan failed (code was mapped to false by $exitCodeMap)
+			wfDebug( __METHOD__ . ": failed to scan $file (code $exitCode).\n" );
+
+			$output = $wgAntivirusRequired
+				? wfMessage( 'virus-scanfailed', [ $exitCode ] )->text()
+				: null;
+		} elseif ( $mappedCode === AV_SCAN_ABORTED ) {
+			# scan failed because filetype is unknown (probably imune)
+			wfDebug( __METHOD__ . ": unsupported file type $file (code $exitCode).\n" );
+			$output = null;
+		} elseif ( $mappedCode === AV_NO_VIRUS ) {
+			# no virus found
+			wfDebug( __METHOD__ . ": file passed virus scan.\n" );
+			$output = false;
+		} else {
+			$output = trim( $output );
+
+			if ( !$output ) {
+				$output = true; # if there's no output, return true
+			} elseif ( $msgPattern ) {
+				$groups = [];
+				if ( preg_match( $msgPattern, $output, $groups ) ) {
+					if ( $groups[1] ) {
+						$output = $groups[1];
+					}
+				}
+			}
+
+			wfDebug( __METHOD__ . ": FOUND VIRUS! scanner feedback: $output \n" );
+		}
+
+		return $output;
+	}
+
+	/**
+	 * Check if there's an overwrite conflict and, if so, if restrictions
+	 * forbid this user from performing the upload.
+	 *
+	 * @param User $user
+	 *
+	 * @return mixed True on success, array on failure
+	 */
+	private function checkOverwrite( $user ) {
+		// First check whether the local file can be overwritten
+		$file = $this->getLocalFile();
+		$file->load( File::READ_LATEST );
+		if ( $file->exists() ) {
+			if ( !self::userCanReUpload( $user, $file ) ) {
+				return [ 'fileexists-forbidden', $file->getName() ];
+			} else {
+				return true;
+			}
+		}
+
+		/* Check shared conflicts: if the local file does not exist, but
+		 * wfFindFile finds a file, it exists in a shared repository.
+		 */
+		$file = wfFindFile( $this->getTitle(), [ 'latest' => true ] );
+		if ( $file && !$user->isAllowed( 'reupload-shared' ) ) {
+			return [ 'fileexists-shared-forbidden', $file->getName() ];
+		}
+
+		return true;
+	}
+
+	/**
+	 * Check if a user is the last uploader
+	 *
+	 * @param User $user
+	 * @param File $img
+	 * @return bool
+	 */
+	public static function userCanReUpload( User $user, File $img ) {
+		if ( $user->isAllowed( 'reupload' ) ) {
+			return true; // non-conditional
+		} elseif ( !$user->isAllowed( 'reupload-own' ) ) {
+			return false;
+		}
+
+		if ( !( $img instanceof LocalFile ) ) {
+			return false;
+		}
+
+		$img->load();
+
+		return $user->getId() == $img->getUser( 'id' );
+	}
+
+	/**
+	 * Helper function that does various existence checks for a file.
+	 * The following checks are performed:
+	 * - The file exists
+	 * - Article with the same name as the file exists
+	 * - File exists with normalized extension
+	 * - The file looks like a thumbnail and the original exists
+	 *
+	 * @param File $file The File object to check
+	 * @return mixed False if the file does not exists, else an array
+	 */
+	public static function getExistsWarning( $file ) {
+		if ( $file->exists() ) {
+			return [ 'warning' => 'exists', 'file' => $file ];
+		}
+
+		if ( $file->getTitle()->getArticleID() ) {
+			return [ 'warning' => 'page-exists', 'file' => $file ];
+		}
+
+		if ( strpos( $file->getName(), '.' ) == false ) {
+			$partname = $file->getName();
+			$extension = '';
+		} else {
+			$n = strrpos( $file->getName(), '.' );
+			$extension = substr( $file->getName(), $n + 1 );
+			$partname = substr( $file->getName(), 0, $n );
+		}
+		$normalizedExtension = File::normalizeExtension( $extension );
+
+		if ( $normalizedExtension != $extension ) {
+			// We're not using the normalized form of the extension.
+			// Normal form is lowercase, using most common of alternate
+			// extensions (eg 'jpg' rather than 'JPEG').
+
+			// Check for another file using the normalized form...
+			$nt_lc = Title::makeTitle( NS_FILE, "{$partname}.{$normalizedExtension}" );
+			$file_lc = wfLocalFile( $nt_lc );
+
+			if ( $file_lc->exists() ) {
+				return [
+					'warning' => 'exists-normalized',
+					'file' => $file,
+					'normalizedFile' => $file_lc
+				];
+			}
+		}
+
+		// Check for files with the same name but a different extension
+		$similarFiles = RepoGroup::singleton()->getLocalRepo()->findFilesByPrefix(
+			"{$partname}.", 1 );
+		if ( count( $similarFiles ) ) {
+			return [
+				'warning' => 'exists-normalized',
+				'file' => $file,
+				'normalizedFile' => $similarFiles[0],
+			];
+		}
+
+		if ( self::isThumbName( $file->getName() ) ) {
+			# Check for filenames like 50px- or 180px-, these are mostly thumbnails
+			$nt_thb = Title::newFromText(
+				substr( $partname, strpos( $partname, '-' ) + 1 ) . '.' . $extension,
+				NS_FILE
+			);
+			$file_thb = wfLocalFile( $nt_thb );
+			if ( $file_thb->exists() ) {
+				return [
+					'warning' => 'thumb',
+					'file' => $file,
+					'thumbFile' => $file_thb
+				];
+			} else {
+				// File does not exist, but we just don't like the name
+				return [
+					'warning' => 'thumb-name',
+					'file' => $file,
+					'thumbFile' => $file_thb
+				];
+			}
+		}
+
+		foreach ( self::getFilenamePrefixBlacklist() as $prefix ) {
+			if ( substr( $partname, 0, strlen( $prefix ) ) == $prefix ) {
+				return [
+					'warning' => 'bad-prefix',
+					'file' => $file,
+					'prefix' => $prefix
+				];
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Helper function that checks whether the filename looks like a thumbnail
+	 * @param string $filename
+	 * @return bool
+	 */
+	public static function isThumbName( $filename ) {
+		$n = strrpos( $filename, '.' );
+		$partname = $n ? substr( $filename, 0, $n ) : $filename;
+
+		return (
+			substr( $partname, 3, 3 ) == 'px-' ||
+			substr( $partname, 2, 3 ) == 'px-'
+		) &&
+		preg_match( "/[0-9]{2}/", substr( $partname, 0, 2 ) );
+	}
+
+	/**
+	 * Get a list of blacklisted filename prefixes from [[MediaWiki:Filename-prefix-blacklist]]
+	 *
+	 * @return array List of prefixes
+	 */
+	public static function getFilenamePrefixBlacklist() {
+		$blacklist = [];
+		$message = wfMessage( 'filename-prefix-blacklist' )->inContentLanguage();
+		if ( !$message->isDisabled() ) {
+			$lines = explode( "\n", $message->plain() );
+			foreach ( $lines as $line ) {
+				// Remove comment lines
+				$comment = substr( trim( $line ), 0, 1 );
+				if ( $comment == '#' || $comment == '' ) {
+					continue;
+				}
+				// Remove additional comments after a prefix
+				$comment = strpos( $line, '#' );
+				if ( $comment > 0 ) {
+					$line = substr( $line, 0, $comment - 1 );
+				}
+				$blacklist[] = trim( $line );
+			}
+		}
+
+		return $blacklist;
+	}
+
+	/**
+	 * Gets image info about the file just uploaded.
+	 *
+	 * Also has the effect of setting metadata to be an 'indexed tag name' in
+	 * returned API result if 'metadata' was requested. Oddly, we have to pass
+	 * the "result" object down just so it can do that with the appropriate
+	 * format, presumably.
+	 *
+	 * @param ApiResult $result
+	 * @return array Image info
+	 */
+	public function getImageInfo( $result ) {
+		$localFile = $this->getLocalFile();
+		$stashFile = $this->getStashFile();
+		// Calling a different API module depending on whether the file was stashed is less than optimal.
+		// In fact, calling API modules here at all is less than optimal. Maybe it should be refactored.
+		if ( $stashFile ) {
+			$imParam = ApiQueryStashImageInfo::getPropertyNames();
+			$info = ApiQueryStashImageInfo::getInfo( $stashFile, array_flip( $imParam ), $result );
+		} else {
+			$imParam = ApiQueryImageInfo::getPropertyNames();
+			$info = ApiQueryImageInfo::getInfo( $localFile, array_flip( $imParam ), $result );
+		}
+
+		return $info;
+	}
+
+	/**
+	 * @param array $error
+	 * @return Status
+	 */
+	public function convertVerifyErrorToStatus( $error ) {
+		$code = $error['status'];
+		unset( $code['status'] );
+
+		return Status::newFatal( $this->getVerificationErrorCode( $code ), $error );
+	}
+
+	/**
+	 * Get the MediaWiki maximum uploaded file size for given type of upload, based on
+	 * $wgMaxUploadSize.
+	 *
+	 * @param null|string $forType
+	 * @return int
+	 */
+	public static function getMaxUploadSize( $forType = null ) {
+		global $wgMaxUploadSize;
+
+		if ( is_array( $wgMaxUploadSize ) ) {
+			if ( !is_null( $forType ) && isset( $wgMaxUploadSize[$forType] ) ) {
+				return $wgMaxUploadSize[$forType];
+			} else {
+				return $wgMaxUploadSize['*'];
+			}
+		} else {
+			return intval( $wgMaxUploadSize );
+		}
+	}
+
+	/**
+	 * Get the PHP maximum uploaded file size, based on ini settings. If there is no limit or the
+	 * limit can't be guessed, returns a very large number (PHP_INT_MAX).
+	 *
+	 * @since 1.27
+	 * @return int
+	 */
+	public static function getMaxPhpUploadSize() {
+		$phpMaxFileSize = wfShorthandToInteger(
+			ini_get( 'upload_max_filesize' ) ?: ini_get( 'hhvm.server.upload.upload_max_file_size' ),
+			PHP_INT_MAX
+		);
+		$phpMaxPostSize = wfShorthandToInteger(
+			ini_get( 'post_max_size' ) ?: ini_get( 'hhvm.server.max_post_size' ),
+			PHP_INT_MAX
+		) ?: PHP_INT_MAX;
+		return min( $phpMaxFileSize, $phpMaxPostSize );
+	}
+
+	/**
+	 * Get the current status of a chunked upload (used for polling)
+	 *
+	 * The value will be read from cache.
+	 *
+	 * @param User $user
+	 * @param string $statusKey
+	 * @return Status[]|bool
+	 */
+	public static function getSessionStatus( User $user, $statusKey ) {
+		$cache = MediaWikiServices::getInstance()->getMainObjectStash();
+		$key = $cache->makeKey( 'uploadstatus', $user->getId() ?: md5( $user->getName() ), $statusKey );
+
+		return $cache->get( $key );
+	}
+
+	/**
+	 * Set the current status of a chunked upload (used for polling)
+	 *
+	 * The value will be set in cache for 1 day
+	 *
+	 * @param User $user
+	 * @param string $statusKey
+	 * @param array|bool $value
+	 * @return void
+	 */
+	public static function setSessionStatus( User $user, $statusKey, $value ) {
+		$cache = MediaWikiServices::getInstance()->getMainObjectStash();
+		$key = $cache->makeKey( 'uploadstatus', $user->getId() ?: md5( $user->getName() ), $statusKey );
+
+		if ( $value === false ) {
+			$cache->delete( $key );
+		} else {
+			$cache->set( $key, $value, $cache::TTL_DAY );
+		}
+	}
+}
diff --git a/www/wiki/includes/upload/UploadFromChunks.php b/www/wiki/includes/upload/UploadFromChunks.php
new file mode 100644
index 00000000..68bcb9d9
--- /dev/null
+++ b/www/wiki/includes/upload/UploadFromChunks.php
@@ -0,0 +1,430 @@
+<?php
+/**
+ * Backend for uploading files from chunks.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Upload
+ */
+
+/**
+ * Implements uploading from chunks
+ *
+ * @ingroup Upload
+ * @author Michael Dale
+ */
+class UploadFromChunks extends UploadFromFile {
+	protected $mOffset;
+	protected $mChunkIndex;
+	protected $mFileKey;
+	protected $mVirtualTempPath;
+	/** @var LocalRepo */
+	private $repo;
+
+	/**
+	 * Setup local pointers to stash, repo and user (similar to UploadFromStash)
+	 *
+	 * @param User $user
+	 * @param UploadStash|bool $stash Default: false
+	 * @param FileRepo|bool $repo Default: false
+	 */
+	public function __construct( User $user, $stash = false, $repo = false ) {
+		$this->user = $user;
+
+		if ( $repo ) {
+			$this->repo = $repo;
+		} else {
+			$this->repo = RepoGroup::singleton()->getLocalRepo();
+		}
+
+		if ( $stash ) {
+			$this->stash = $stash;
+		} else {
+			if ( $user ) {
+				wfDebug( __METHOD__ . " creating new UploadFromChunks instance for " . $user->getId() . "\n" );
+			} else {
+				wfDebug( __METHOD__ . " creating new UploadFromChunks instance with no user\n" );
+			}
+			$this->stash = new UploadStash( $this->repo, $this->user );
+		}
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function tryStashFile( User $user, $isPartial = false ) {
+		try {
+			$this->verifyChunk();
+		} catch ( UploadChunkVerificationException $e ) {
+			return Status::newFatal( $e->msg );
+		}
+
+		return parent::tryStashFile( $user, $isPartial );
+	}
+
+	/**
+	 * @inheritDoc
+	 * @throws UploadChunkVerificationException
+	 * @deprecated since 1.28 Use tryStashFile() instead
+	 */
+	public function stashFile( User $user = null ) {
+		wfDeprecated( __METHOD__, '1.28' );
+		$this->verifyChunk();
+		return parent::stashFile( $user );
+	}
+
+	/**
+	 * @inheritDoc
+	 * @throws UploadChunkVerificationException
+	 * @deprecated since 1.28
+	 */
+	public function stashFileGetKey() {
+		wfDeprecated( __METHOD__, '1.28' );
+		$this->verifyChunk();
+		return parent::stashFileGetKey();
+	}
+
+	/**
+	 * @inheritDoc
+	 * @throws UploadChunkVerificationException
+	 * @deprecated since 1.28
+	 */
+	public function stashSession() {
+		wfDeprecated( __METHOD__, '1.28' );
+		$this->verifyChunk();
+		return parent::stashSession();
+	}
+
+	/**
+	 * Calls the parent doStashFile and updates the uploadsession table to handle "chunks"
+	 *
+	 * @param User|null $user
+	 * @return UploadStashFile Stashed file
+	 */
+	protected function doStashFile( User $user = null ) {
+		// Stash file is the called on creating a new chunk session:
+		$this->mChunkIndex = 0;
+		$this->mOffset = 0;
+
+		// Create a local stash target
+		$this->mStashFile = parent::doStashFile( $user );
+		// Update the initial file offset (based on file size)
+		$this->mOffset = $this->mStashFile->getSize();
+		$this->mFileKey = $this->mStashFile->getFileKey();
+
+		// Output a copy of this first to chunk 0 location:
+		$this->outputChunk( $this->mStashFile->getPath() );
+
+		// Update db table to reflect initial "chunk" state
+		$this->updateChunkStatus();
+
+		return $this->mStashFile;
+	}
+
+	/**
+	 * Continue chunk uploading
+	 *
+	 * @param string $name
+	 * @param string $key
+	 * @param WebRequestUpload $webRequestUpload
+	 */
+	public function continueChunks( $name, $key, $webRequestUpload ) {
+		$this->mFileKey = $key;
+		$this->mUpload = $webRequestUpload;
+		// Get the chunk status form the db:
+		$this->getChunkStatus();
+
+		$metadata = $this->stash->getMetadata( $key );
+		$this->initializePathInfo( $name,
+			$this->getRealPath( $metadata['us_path'] ),
+			$metadata['us_size'],
+			false
+		);
+	}
+
+	/**
+	 * Append the final chunk and ready file for parent::performUpload()
+	 * @return Status
+	 */
+	public function concatenateChunks() {
+		$chunkIndex = $this->getChunkIndex();
+		wfDebug( __METHOD__ . " concatenate {$this->mChunkIndex} chunks:" .
+			$this->getOffset() . ' inx:' . $chunkIndex . "\n" );
+
+		// Concatenate all the chunks to mVirtualTempPath
+		$fileList = [];
+		// The first chunk is stored at the mVirtualTempPath path so we start on "chunk 1"
+		for ( $i = 0; $i <= $chunkIndex; $i++ ) {
+			$fileList[] = $this->getVirtualChunkLocation( $i );
+		}
+
+		// Get the file extension from the last chunk
+		$ext = FileBackend::extensionFromPath( $this->mVirtualTempPath );
+		// Get a 0-byte temp file to perform the concatenation at
+		$tmpFile = TempFSFile::factory( 'chunkedupload_', $ext, wfTempDir() );
+		$tmpPath = false; // fail in concatenate()
+		if ( $tmpFile ) {
+			// keep alive with $this
+			$tmpPath = $tmpFile->bind( $this )->getPath();
+		}
+
+		// Concatenate the chunks at the temp file
+		$tStart = microtime( true );
+		$status = $this->repo->concatenate( $fileList, $tmpPath, FileRepo::DELETE_SOURCE );
+		$tAmount = microtime( true ) - $tStart;
+		if ( !$status->isOK() ) {
+			return $status;
+		}
+
+		wfDebugLog( 'fileconcatenate', "Combined $i chunks in $tAmount seconds." );
+
+		// File system path of the actual full temp file
+		$this->setTempFile( $tmpPath );
+
+		$ret = $this->verifyUpload();
+		if ( $ret['status'] !== UploadBase::OK ) {
+			wfDebugLog( 'fileconcatenate', "Verification failed for chunked upload" );
+			$status->fatal( $this->getVerificationErrorCode( $ret['status'] ) );
+
+			return $status;
+		}
+
+		// Update the mTempPath and mStashFile
+		// (for FileUpload or normal Stash to take over)
+		$tStart = microtime( true );
+		// This is a re-implementation of UploadBase::tryStashFile(), we can't call it because we
+		// override doStashFile() with completely different functionality in this class...
+		$error = $this->runUploadStashFileHook( $this->user );
+		if ( $error ) {
+			call_user_func_array( [ $status, 'fatal' ], $error );
+			return $status;
+		}
+		try {
+			$this->mStashFile = parent::doStashFile( $this->user );
+		} catch ( UploadStashException $e ) {
+			$status->fatal( 'uploadstash-exception', get_class( $e ), $e->getMessage() );
+			return $status;
+		}
+
+		$tAmount = microtime( true ) - $tStart;
+		$this->mStashFile->setLocalReference( $tmpFile ); // reuse (e.g. for getImageInfo())
+		wfDebugLog( 'fileconcatenate', "Stashed combined file ($i chunks) in $tAmount seconds." );
+
+		return $status;
+	}
+
+	/**
+	 * Returns the virtual chunk location:
+	 * @param int $index
+	 * @return string
+	 */
+	function getVirtualChunkLocation( $index ) {
+		return $this->repo->getVirtualUrl( 'temp' ) .
+			'/' .
+			$this->repo->getHashPath(
+				$this->getChunkFileKey( $index )
+			) .
+			$this->getChunkFileKey( $index );
+	}
+
+	/**
+	 * Add a chunk to the temporary directory
+	 *
+	 * @param string $chunkPath Path to temporary chunk file
+	 * @param int $chunkSize Size of the current chunk
+	 * @param int $offset Offset of current chunk ( mutch match database chunk offset )
+	 * @return Status
+	 */
+	public function addChunk( $chunkPath, $chunkSize, $offset ) {
+		// Get the offset before we add the chunk to the file system
+		$preAppendOffset = $this->getOffset();
+
+		if ( $preAppendOffset + $chunkSize > $this->getMaxUploadSize() ) {
+			$status = Status::newFatal( 'file-too-large' );
+		} else {
+			// Make sure the client is uploading the correct chunk with a matching offset.
+			if ( $preAppendOffset == $offset ) {
+				// Update local chunk index for the current chunk
+				$this->mChunkIndex++;
+				try {
+					# For some reason mTempPath is set to first part
+					$oldTemp = $this->mTempPath;
+					$this->mTempPath = $chunkPath;
+					$this->verifyChunk();
+					$this->mTempPath = $oldTemp;
+				} catch ( UploadChunkVerificationException $e ) {
+					return Status::newFatal( $e->msg );
+				}
+				$status = $this->outputChunk( $chunkPath );
+				if ( $status->isGood() ) {
+					// Update local offset:
+					$this->mOffset = $preAppendOffset + $chunkSize;
+					// Update chunk table status db
+					$this->updateChunkStatus();
+				}
+			} else {
+				$status = Status::newFatal( 'invalid-chunk-offset' );
+			}
+		}
+
+		return $status;
+	}
+
+	/**
+	 * Update the chunk db table with the current status:
+	 */
+	private function updateChunkStatus() {
+		wfDebug( __METHOD__ . " update chunk status for {$this->mFileKey} offset:" .
+			$this->getOffset() . ' inx:' . $this->getChunkIndex() . "\n" );
+
+		$dbw = $this->repo->getMasterDB();
+		$dbw->update(
+			'uploadstash',
+			[
+				'us_status' => 'chunks',
+				'us_chunk_inx' => $this->getChunkIndex(),
+				'us_size' => $this->getOffset()
+			],
+			[ 'us_key' => $this->mFileKey ],
+			__METHOD__
+		);
+	}
+
+	/**
+	 * Get the chunk db state and populate update relevant local values
+	 */
+	private function getChunkStatus() {
+		// get Master db to avoid race conditions.
+		// Otherwise, if chunk upload time < replag there will be spurious errors
+		$dbw = $this->repo->getMasterDB();
+		$row = $dbw->selectRow(
+			'uploadstash',
+			[
+				'us_chunk_inx',
+				'us_size',
+				'us_path',
+			],
+			[ 'us_key' => $this->mFileKey ],
+			__METHOD__
+		);
+		// Handle result:
+		if ( $row ) {
+			$this->mChunkIndex = $row->us_chunk_inx;
+			$this->mOffset = $row->us_size;
+			$this->mVirtualTempPath = $row->us_path;
+		}
+	}
+
+	/**
+	 * Get the current Chunk index
+	 * @return int Index of the current chunk
+	 */
+	private function getChunkIndex() {
+		if ( $this->mChunkIndex !== null ) {
+			return $this->mChunkIndex;
+		}
+
+		return 0;
+	}
+
+	/**
+	 * Get the offset at which the next uploaded chunk will be appended to
+	 * @return int Current byte offset of the chunk file set
+	 */
+	public function getOffset() {
+		if ( $this->mOffset !== null ) {
+			return $this->mOffset;
+		}
+
+		return 0;
+	}
+
+	/**
+	 * Output the chunk to disk
+	 *
+	 * @param string $chunkPath
+	 * @throws UploadChunkFileException
+	 * @return Status
+	 */
+	private function outputChunk( $chunkPath ) {
+		// Key is fileKey + chunk index
+		$fileKey = $this->getChunkFileKey();
+
+		// Store the chunk per its indexed fileKey:
+		$hashPath = $this->repo->getHashPath( $fileKey );
+		$storeStatus = $this->repo->quickImport( $chunkPath,
+			$this->repo->getZonePath( 'temp' ) . "/{$hashPath}{$fileKey}" );
+
+		// Check for error in stashing the chunk:
+		if ( !$storeStatus->isOK() ) {
+			$error = $storeStatus->getErrorsArray();
+			$error = reset( $error );
+			if ( !count( $error ) ) {
+				$error = $storeStatus->getWarningsArray();
+				$error = reset( $error );
+				if ( !count( $error ) ) {
+					$error = [ 'unknown', 'no error recorded' ];
+				}
+			}
+			throw new UploadChunkFileException( "Error storing file in '$chunkPath': " .
+				implode( '; ', $error ) );
+		}
+
+		return $storeStatus;
+	}
+
+	private function getChunkFileKey( $index = null ) {
+		if ( $index === null ) {
+			$index = $this->getChunkIndex();
+		}
+
+		return $this->mFileKey . '.' . $index;
+	}
+
+	/**
+	 * Verify that the chunk isn't really an evil html file
+	 *
+	 * @throws UploadChunkVerificationException
+	 */
+	private function verifyChunk() {
+		// Rest mDesiredDestName here so we verify the name as if it were mFileKey
+		$oldDesiredDestName = $this->mDesiredDestName;
+		$this->mDesiredDestName = $this->mFileKey;
+		$this->mTitle = false;
+		$res = $this->verifyPartialFile();
+		$this->mDesiredDestName = $oldDesiredDestName;
+		$this->mTitle = false;
+		if ( is_array( $res ) ) {
+			throw new UploadChunkVerificationException( $res );
+		}
+	}
+}
+
+class UploadChunkZeroLengthFileException extends MWException {
+}
+
+class UploadChunkFileException extends MWException {
+}
+
+class UploadChunkVerificationException extends MWException {
+	public $msg;
+	public function __construct( $res ) {
+		$this->msg = call_user_func_array( 'wfMessage', $res );
+		parent::__construct( call_user_func_array( 'wfMessage', $res )
+			->inLanguage( 'en' )->useDatabase( false )->text() );
+	}
+}
diff --git a/www/wiki/includes/upload/UploadFromFile.php b/www/wiki/includes/upload/UploadFromFile.php
new file mode 100644
index 00000000..675bb8d4
--- /dev/null
+++ b/www/wiki/includes/upload/UploadFromFile.php
@@ -0,0 +1,97 @@
+<?php
+/**
+ * Backend for regular file upload.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Upload
+ */
+
+/**
+ * Implements regular file uploads
+ *
+ * @ingroup Upload
+ * @author Bryan Tong Minh
+ */
+class UploadFromFile extends UploadBase {
+	/**
+	 * @var WebRequestUpload
+	 */
+	protected $mUpload = null;
+
+	/**
+	 * @param WebRequest &$request
+	 */
+	function initializeFromRequest( &$request ) {
+		$upload = $request->getUpload( 'wpUploadFile' );
+		$desiredDestName = $request->getText( 'wpDestFile' );
+		if ( !$desiredDestName ) {
+			$desiredDestName = $upload->getName();
+		}
+
+		$this->initialize( $desiredDestName, $upload );
+	}
+
+	/**
+	 * Initialize from a filename and a WebRequestUpload
+	 * @param string $name
+	 * @param WebRequestUpload $webRequestUpload
+	 */
+	function initialize( $name, $webRequestUpload ) {
+		$this->mUpload = $webRequestUpload;
+		$this->initializePathInfo( $name,
+			$this->mUpload->getTempName(), $this->mUpload->getSize() );
+	}
+
+	/**
+	 * @param WebRequest $request
+	 * @return bool
+	 */
+	static function isValidRequest( $request ) {
+		# Allow all requests, even if no file is present, so that an error
+		# because a post_max_size or upload_max_filesize overflow
+		return true;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getSourceType() {
+		return 'file';
+	}
+
+	/**
+	 * @return array
+	 */
+	public function verifyUpload() {
+		# Check for a post_max_size or upload_max_size overflow, so that a
+		# proper error can be shown to the user
+		if ( is_null( $this->mTempPath ) || $this->isEmptyFile() ) {
+			if ( $this->mUpload->isIniSizeOverflow() ) {
+				return [
+					'status' => UploadBase::FILE_TOO_LARGE,
+					'max' => min(
+						self::getMaxUploadSize( $this->getSourceType() ),
+						self::getMaxPhpUploadSize()
+					),
+				];
+			}
+		}
+
+		return parent::verifyUpload();
+	}
+}
diff --git a/www/wiki/includes/upload/UploadFromStash.php b/www/wiki/includes/upload/UploadFromStash.php
new file mode 100644
index 00000000..a9f399b7
--- /dev/null
+++ b/www/wiki/includes/upload/UploadFromStash.php
@@ -0,0 +1,161 @@
+<?php
+/**
+ * Backend for uploading files from previously stored file.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Upload
+ */
+
+/**
+ * Implements uploading from previously stored file.
+ *
+ * @ingroup Upload
+ * @author Bryan Tong Minh
+ */
+class UploadFromStash extends UploadBase {
+	protected $mFileKey;
+	protected $mVirtualTempPath;
+	protected $mFileProps;
+	protected $mSourceType;
+
+	// an instance of UploadStash
+	private $stash;
+
+	// LocalFile repo
+	private $repo;
+
+	/**
+	 * @param User|bool $user Default: false
+	 * @param UploadStash|bool $stash Default: false
+	 * @param FileRepo|bool $repo Default: false
+	 */
+	public function __construct( $user = false, $stash = false, $repo = false ) {
+		// user object. sometimes this won't exist, as when running from cron.
+		$this->user = $user;
+
+		if ( $repo ) {
+			$this->repo = $repo;
+		} else {
+			$this->repo = RepoGroup::singleton()->getLocalRepo();
+		}
+
+		if ( $stash ) {
+			$this->stash = $stash;
+		} else {
+			if ( $user ) {
+				wfDebug( __METHOD__ . " creating new UploadStash instance for " . $user->getId() . "\n" );
+			} else {
+				wfDebug( __METHOD__ . " creating new UploadStash instance with no user\n" );
+			}
+
+			$this->stash = new UploadStash( $this->repo, $this->user );
+		}
+	}
+
+	/**
+	 * @param string $key
+	 * @return bool
+	 */
+	public static function isValidKey( $key ) {
+		// this is checked in more detail in UploadStash
+		return (bool)preg_match( UploadStash::KEY_FORMAT_REGEX, $key );
+	}
+
+	/**
+	 * @param WebRequest $request
+	 * @return bool
+	 */
+	public static function isValidRequest( $request ) {
+		// this passes wpSessionKey to getText() as a default when wpFileKey isn't set.
+		// wpSessionKey has no default which guarantees failure if both are missing
+		// (though that should have been caught earlier)
+		return self::isValidKey( $request->getText( 'wpFileKey', $request->getText( 'wpSessionKey' ) ) );
+	}
+
+	/**
+	 * @param string $key
+	 * @param string $name
+	 * @param bool $initTempFile
+	 */
+	public function initialize( $key, $name = 'upload_file', $initTempFile = true ) {
+		/**
+		 * Confirming a temporarily stashed upload.
+		 * We don't want path names to be forged, so we keep
+		 * them in the session on the server and just give
+		 * an opaque key to the user agent.
+		 */
+		$metadata = $this->stash->getMetadata( $key );
+		$this->initializePathInfo( $name,
+			$initTempFile ? $this->getRealPath( $metadata['us_path'] ) : false,
+			$metadata['us_size'],
+			false
+		);
+
+		$this->mFileKey = $key;
+		$this->mVirtualTempPath = $metadata['us_path'];
+		$this->mFileProps = $this->stash->getFileProps( $key );
+		$this->mSourceType = $metadata['us_source_type'];
+	}
+
+	/**
+	 * @param WebRequest &$request
+	 */
+	public function initializeFromRequest( &$request ) {
+		// sends wpSessionKey as a default when wpFileKey is missing
+		$fileKey = $request->getText( 'wpFileKey', $request->getText( 'wpSessionKey' ) );
+
+		// chooses one of wpDestFile, wpUploadFile, filename in that order.
+		$desiredDestName = $request->getText(
+			'wpDestFile',
+			$request->getText( 'wpUploadFile', $request->getText( 'filename' ) )
+		);
+
+		$this->initialize( $fileKey, $desiredDestName );
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getSourceType() {
+		return $this->mSourceType;
+	}
+
+	/**
+	 * Get the base 36 SHA1 of the file
+	 * @return string
+	 */
+	public function getTempFileSha1Base36() {
+		return $this->mFileProps['sha1'];
+	}
+
+	/**
+	 * Remove a temporarily kept file stashed by saveTempUploadedFile().
+	 * @return bool Success
+	 */
+	public function unsaveUploadedFile() {
+		return $this->stash->removeFile( $this->mFileKey );
+	}
+
+	/**
+	 * Remove the database record after a successful upload.
+	 */
+	public function postProcessUpload() {
+		parent::postProcessUpload();
+		$this->unsaveUploadedFile();
+	}
+}
diff --git a/www/wiki/includes/upload/UploadFromUrl.php b/www/wiki/includes/upload/UploadFromUrl.php
new file mode 100644
index 00000000..f5367bb6
--- /dev/null
+++ b/www/wiki/includes/upload/UploadFromUrl.php
@@ -0,0 +1,300 @@
+<?php
+/**
+ * Backend for uploading files from a HTTP resource.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup Upload
+ */
+
+/**
+ * Implements uploading from a HTTP resource.
+ *
+ * @ingroup Upload
+ * @author Bryan Tong Minh
+ * @author Michael Dale
+ */
+class UploadFromUrl extends UploadBase {
+	protected $mUrl;
+
+	protected $mTempPath, $mTmpHandle;
+
+	protected static $allowedUrls = [];
+
+	/**
+	 * Checks if the user is allowed to use the upload-by-URL feature. If the
+	 * user is not allowed, return the name of the user right as a string. If
+	 * the user is allowed, have the parent do further permissions checking.
+	 *
+	 * @param User $user
+	 *
+	 * @return bool|string
+	 */
+	public static function isAllowed( $user ) {
+		if ( !$user->isAllowed( 'upload_by_url' ) ) {
+			return 'upload_by_url';
+		}
+
+		return parent::isAllowed( $user );
+	}
+
+	/**
+	 * Checks if the upload from URL feature is enabled
+	 * @return bool
+	 */
+	public static function isEnabled() {
+		global $wgAllowCopyUploads;
+
+		return $wgAllowCopyUploads && parent::isEnabled();
+	}
+
+	/**
+	 * Checks whether the URL is for an allowed host
+	 * The domains in the whitelist can include wildcard characters (*) in place
+	 * of any of the domain levels, e.g. '*.flickr.com' or 'upload.*.gov.uk'.
+	 *
+	 * @param string $url
+	 * @return bool
+	 */
+	public static function isAllowedHost( $url ) {
+		global $wgCopyUploadsDomains;
+		if ( !count( $wgCopyUploadsDomains ) ) {
+			return true;
+		}
+		$parsedUrl = wfParseUrl( $url );
+		if ( !$parsedUrl ) {
+			return false;
+		}
+		$valid = false;
+		foreach ( $wgCopyUploadsDomains as $domain ) {
+			// See if the domain for the upload matches this whitelisted domain
+			$whitelistedDomainPieces = explode( '.', $domain );
+			$uploadDomainPieces = explode( '.', $parsedUrl['host'] );
+			if ( count( $whitelistedDomainPieces ) === count( $uploadDomainPieces ) ) {
+				$valid = true;
+				// See if all the pieces match or not (excluding wildcards)
+				foreach ( $whitelistedDomainPieces as $index => $piece ) {
+					if ( $piece !== '*' && $piece !== $uploadDomainPieces[$index] ) {
+						$valid = false;
+					}
+				}
+				if ( $valid ) {
+					// We found a match, so quit comparing against the list
+					break;
+				}
+			}
+			/* Non-wildcard test
+			if ( $parsedUrl['host'] === $domain ) {
+				$valid = true;
+				break;
+			}
+			*/
+		}
+
+		return $valid;
+	}
+
+	/**
+	 * Checks whether the URL is not allowed.
+	 *
+	 * @param string $url
+	 * @return bool
+	 */
+	public static function isAllowedUrl( $url ) {
+		if ( !isset( self::$allowedUrls[$url] ) ) {
+			$allowed = true;
+			Hooks::run( 'IsUploadAllowedFromUrl', [ $url, &$allowed ] );
+			self::$allowedUrls[$url] = $allowed;
+		}
+
+		return self::$allowedUrls[$url];
+	}
+
+	/**
+	 * Entry point for API upload
+	 *
+	 * @param string $name
+	 * @param string $url
+	 * @throws MWException
+	 */
+	public function initialize( $name, $url ) {
+		$this->mUrl = $url;
+
+		$tempPath = $this->makeTemporaryFile();
+		# File size and removeTempFile will be filled in later
+		$this->initializePathInfo( $name, $tempPath, 0, false );
+	}
+
+	/**
+	 * Entry point for SpecialUpload
+	 * @param WebRequest &$request
+	 */
+	public function initializeFromRequest( &$request ) {
+		$desiredDestName = $request->getText( 'wpDestFile' );
+		if ( !$desiredDestName ) {
+			$desiredDestName = $request->getText( 'wpUploadFileURL' );
+		}
+		$this->initialize(
+			$desiredDestName,
+			trim( $request->getVal( 'wpUploadFileURL' ) ),
+			false
+		);
+	}
+
+	/**
+	 * @param WebRequest $request
+	 * @return bool
+	 */
+	public static function isValidRequest( $request ) {
+		global $wgUser;
+
+		$url = $request->getVal( 'wpUploadFileURL' );
+
+		return !empty( $url )
+			&& $wgUser->isAllowed( 'upload_by_url' );
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getSourceType() {
+		return 'url';
+	}
+
+	/**
+	 * Download the file
+	 *
+	 * @param array $httpOptions Array of options for MWHttpRequest.
+	 *   This could be used to override the timeout on the http request.
+	 * @return Status
+	 */
+	public function fetchFile( $httpOptions = [] ) {
+		if ( !Http::isValidURI( $this->mUrl ) ) {
+			return Status::newFatal( 'http-invalid-url', $this->mUrl );
+		}
+
+		if ( !self::isAllowedHost( $this->mUrl ) ) {
+			return Status::newFatal( 'upload-copy-upload-invalid-domain' );
+		}
+		if ( !self::isAllowedUrl( $this->mUrl ) ) {
+			return Status::newFatal( 'upload-copy-upload-invalid-url' );
+		}
+		return $this->reallyFetchFile( $httpOptions );
+	}
+
+	/**
+	 * Create a new temporary file in the URL subdirectory of wfTempDir().
+	 *
+	 * @return string Path to the file
+	 */
+	protected function makeTemporaryFile() {
+		$tmpFile = TempFSFile::factory( 'URL', 'urlupload_', wfTempDir() );
+		$tmpFile->bind( $this );
+
+		return $tmpFile->getPath();
+	}
+
+	/**
+	 * Callback: save a chunk of the result of a HTTP request to the temporary file
+	 *
+	 * @param mixed $req
+	 * @param string $buffer
+	 * @return int Number of bytes handled
+	 */
+	public function saveTempFileChunk( $req, $buffer ) {
+		wfDebugLog( 'fileupload', 'Received chunk of ' . strlen( $buffer ) . ' bytes' );
+		$nbytes = fwrite( $this->mTmpHandle, $buffer );
+
+		if ( $nbytes == strlen( $buffer ) ) {
+			$this->mFileSize += $nbytes;
+		} else {
+			// Well... that's not good!
+			wfDebugLog(
+				'fileupload',
+				'Short write ' . $nbytes . '/' . strlen( $buffer ) .
+					' bytes, aborting with ' . $this->mFileSize . ' uploaded so far'
+			);
+			fclose( $this->mTmpHandle );
+			$this->mTmpHandle = false;
+		}
+
+		return $nbytes;
+	}
+
+	/**
+	 * Download the file, save it to the temporary file and update the file
+	 * size and set $mRemoveTempFile to true.
+	 *
+	 * @param array $httpOptions Array of options for MWHttpRequest
+	 * @return Status
+	 */
+	protected function reallyFetchFile( $httpOptions = [] ) {
+		global $wgCopyUploadProxy, $wgCopyUploadTimeout;
+		if ( $this->mTempPath === false ) {
+			return Status::newFatal( 'tmp-create-error' );
+		}
+
+		// Note the temporary file should already be created by makeTemporaryFile()
+		$this->mTmpHandle = fopen( $this->mTempPath, 'wb' );
+		if ( !$this->mTmpHandle ) {
+			return Status::newFatal( 'tmp-create-error' );
+		}
+		wfDebugLog( 'fileupload', 'Temporary file created "' . $this->mTempPath . '"' );
+
+		$this->mRemoveTempFile = true;
+		$this->mFileSize = 0;
+
+		$options = $httpOptions + [ 'followRedirects' => true ];
+
+		if ( $wgCopyUploadProxy !== false ) {
+			$options['proxy'] = $wgCopyUploadProxy;
+		}
+
+		if ( $wgCopyUploadTimeout && !isset( $options['timeout'] ) ) {
+			$options['timeout'] = $wgCopyUploadTimeout;
+		}
+		wfDebugLog(
+			'fileupload',
+			'Starting download from "' . $this->mUrl . '" ' .
+				'<' . implode( ',', array_keys( array_filter( $options ) ) ) . '>'
+		);
+		$req = MWHttpRequest::factory( $this->mUrl, $options, __METHOD__ );
+		$req->setCallback( [ $this, 'saveTempFileChunk' ] );
+		$status = $req->execute();
+
+		if ( $this->mTmpHandle ) {
+			// File got written ok...
+			fclose( $this->mTmpHandle );
+			$this->mTmpHandle = null;
+		} else {
+			// We encountered a write error during the download...
+			return Status::newFatal( 'tmp-write-error' );
+		}
+
+		wfDebugLog( 'fileupload', $status );
+		if ( $status->isOK() ) {
+			wfDebugLog( 'fileupload', 'Download by URL completed successfully.' );
+		} else {
+			wfDebugLog(
+				'fileupload',
+				'Download by URL completed with HTTP status ' . $req->getStatus()
+			);
+		}
+
+		return $status;
+	}
+}
diff --git a/www/wiki/includes/upload/UploadStash.php b/www/wiki/includes/upload/UploadStash.php
new file mode 100644
index 00000000..e55ab1fb
--- /dev/null
+++ b/www/wiki/includes/upload/UploadStash.php
@@ -0,0 +1,836 @@
+<?php
+/**
+ * Temporary storage for uploaded files.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * UploadStash is intended to accomplish a few things:
+ *   - Enable applications to temporarily stash files without publishing them to
+ *     the wiki.
+ *      - Several parts of MediaWiki do this in similar ways: UploadBase,
+ *        UploadWizard, and FirefoggChunkedExtension.
+ *        And there are several that reimplement stashing from scratch, in
+ *        idiosyncratic ways. The idea is to unify them all here.
+ *        Mostly all of them are the same except for storing some custom fields,
+ *        which we subsume into the data array.
+ *   - Enable applications to find said files later, as long as the db table or
+ *     temp files haven't been purged.
+ *   - Enable the uploading user (and *ONLY* the uploading user) to access said
+ *     files, and thumbnails of said files, via a URL. We accomplish this using
+ *     a database table, with ownership checking as you might expect. See
+ *     SpecialUploadStash, which implements a web interface to some files stored
+ *     this way.
+ *
+ * UploadStash right now is *mostly* intended to show you one user's slice of
+ * the entire stash. The user parameter is only optional because there are few
+ * cases where we clean out the stash from an automated script. In the future we
+ * might refactor this.
+ *
+ * UploadStash represents the entire stash of temporary files.
+ * UploadStashFile is a filestore for the actual physical disk files.
+ * UploadFromStash extends UploadBase, and represents a single stashed file as
+ * it is moved from the stash to the regular file repository
+ *
+ * @ingroup Upload
+ */
+class UploadStash {
+	// Format of the key for files -- has to be suitable as a filename itself (e.g. ab12cd34ef.jpg)
+	const KEY_FORMAT_REGEX = '/^[\w\-\.]+\.\w*$/';
+	const MAX_US_PROPS_SIZE = 65535;
+
+	/**
+	 * repository that this uses to store temp files
+	 * public because we sometimes need to get a LocalFile within the same repo.
+	 *
+	 * @var LocalRepo
+	 */
+	public $repo;
+
+	// array of initialized repo objects
+	protected $files = [];
+
+	// cache of the file metadata that's stored in the database
+	protected $fileMetadata = [];
+
+	// fileprops cache
+	protected $fileProps = [];
+
+	// current user
+	protected $user, $userId, $isLoggedIn;
+
+	/**
+	 * Represents a temporary filestore, with metadata in the database.
+	 * Designed to be compatible with the session stashing code in UploadBase
+	 * (should replace it eventually).
+	 *
+	 * @param FileRepo $repo
+	 * @param User $user (default null)
+	 */
+	public function __construct( FileRepo $repo, $user = null ) {
+		// this might change based on wiki's configuration.
+		$this->repo = $repo;
+
+		// if a user was passed, use it. otherwise, attempt to use the global.
+		// this keeps FileRepo from breaking when it creates an UploadStash object
+		if ( $user ) {
+			$this->user = $user;
+		} else {
+			global $wgUser;
+			$this->user = $wgUser;
+		}
+
+		if ( is_object( $this->user ) ) {
+			$this->userId = $this->user->getId();
+			$this->isLoggedIn = $this->user->isLoggedIn();
+		}
+	}
+
+	/**
+	 * Get a file and its metadata from the stash.
+	 * The noAuth param is a bit janky but is required for automated scripts
+	 * which clean out the stash.
+	 *
+	 * @param string $key Key under which file information is stored
+	 * @param bool $noAuth (optional) Don't check authentication. Used by maintenance scripts.
+	 * @throws UploadStashFileNotFoundException
+	 * @throws UploadStashNotLoggedInException
+	 * @throws UploadStashWrongOwnerException
+	 * @throws UploadStashBadPathException
+	 * @return UploadStashFile
+	 */
+	public function getFile( $key, $noAuth = false ) {
+		if ( !preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
+			throw new UploadStashBadPathException(
+				wfMessage( 'uploadstash-bad-path-bad-format', $key )
+			);
+		}
+
+		if ( !$noAuth && !$this->isLoggedIn ) {
+			throw new UploadStashNotLoggedInException(
+				wfMessage( 'uploadstash-not-logged-in' )
+			);
+		}
+
+		if ( !isset( $this->fileMetadata[$key] ) ) {
+			if ( !$this->fetchFileMetadata( $key ) ) {
+				// If nothing was received, it's likely due to replication lag.
+				// Check the master to see if the record is there.
+				$this->fetchFileMetadata( $key, DB_MASTER );
+			}
+
+			if ( !isset( $this->fileMetadata[$key] ) ) {
+				throw new UploadStashFileNotFoundException(
+					wfMessage( 'uploadstash-file-not-found', $key )
+				);
+			}
+
+			// create $this->files[$key]
+			$this->initFile( $key );
+
+			// fetch fileprops
+			if ( strlen( $this->fileMetadata[$key]['us_props'] ) ) {
+				$this->fileProps[$key] = unserialize( $this->fileMetadata[$key]['us_props'] );
+			} else { // b/c for rows with no us_props
+				wfDebug( __METHOD__ . " fetched props for $key from file\n" );
+				$path = $this->fileMetadata[$key]['us_path'];
+				$this->fileProps[$key] = $this->repo->getFileProps( $path );
+			}
+		}
+
+		if ( !$this->files[$key]->exists() ) {
+			wfDebug( __METHOD__ . " tried to get file at $key, but it doesn't exist\n" );
+			// @todo Is this not an UploadStashFileNotFoundException case?
+			throw new UploadStashBadPathException(
+				wfMessage( 'uploadstash-bad-path' )
+			);
+		}
+
+		if ( !$noAuth ) {
+			if ( $this->fileMetadata[$key]['us_user'] != $this->userId ) {
+				throw new UploadStashWrongOwnerException(
+					wfMessage( 'uploadstash-wrong-owner', $key )
+				);
+			}
+		}
+
+		return $this->files[$key];
+	}
+
+	/**
+	 * Getter for file metadata.
+	 *
+	 * @param string $key Key under which file information is stored
+	 * @return array
+	 */
+	public function getMetadata( $key ) {
+		$this->getFile( $key );
+
+		return $this->fileMetadata[$key];
+	}
+
+	/**
+	 * Getter for fileProps
+	 *
+	 * @param string $key Key under which file information is stored
+	 * @return array
+	 */
+	public function getFileProps( $key ) {
+		$this->getFile( $key );
+
+		return $this->fileProps[$key];
+	}
+
+	/**
+	 * Stash a file in a temp directory and record that we did this in the
+	 * database, along with other metadata.
+	 *
+	 * @param string $path Path to file you want stashed
+	 * @param string $sourceType The type of upload that generated this file
+	 *   (currently, I believe, 'file' or null)
+	 * @throws UploadStashBadPathException
+	 * @throws UploadStashFileException
+	 * @throws UploadStashNotLoggedInException
+	 * @return UploadStashFile|null File, or null on failure
+	 */
+	public function stashFile( $path, $sourceType = null ) {
+		if ( !is_file( $path ) ) {
+			wfDebug( __METHOD__ . " tried to stash file at '$path', but it doesn't exist\n" );
+			throw new UploadStashBadPathException(
+				wfMessage( 'uploadstash-bad-path' )
+			);
+		}
+
+		$mwProps = new MWFileProps( MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer() );
+		$fileProps = $mwProps->getPropsFromPath( $path, true );
+		wfDebug( __METHOD__ . " stashing file at '$path'\n" );
+
+		// we will be initializing from some tmpnam files that don't have extensions.
+		// most of MediaWiki assumes all uploaded files have good extensions. So, we fix this.
+		$extension = self::getExtensionForPath( $path );
+		if ( !preg_match( "/\\.\\Q$extension\\E$/", $path ) ) {
+			$pathWithGoodExtension = "$path.$extension";
+		} else {
+			$pathWithGoodExtension = $path;
+		}
+
+		// If no key was supplied, make one.  a mysql insertid would be totally
+		// reasonable here, except that for historical reasons, the key is this
+		// random thing instead.  At least it's not guessable.
+		// Some things that when combined will make a suitably unique key.
+		// see: http://www.jwz.org/doc/mid.html
+		list( $usec, $sec ) = explode( ' ', microtime() );
+		$usec = substr( $usec, 2 );
+		$key = Wikimedia\base_convert( $sec . $usec, 10, 36 ) . '.' .
+			Wikimedia\base_convert( mt_rand(), 10, 36 ) . '.' .
+			$this->userId . '.' .
+			$extension;
+
+		$this->fileProps[$key] = $fileProps;
+
+		if ( !preg_match( self::KEY_FORMAT_REGEX, $key ) ) {
+			throw new UploadStashBadPathException(
+				wfMessage( 'uploadstash-bad-path-bad-format', $key )
+			);
+		}
+
+		wfDebug( __METHOD__ . " key for '$path': $key\n" );
+
+		// if not already in a temporary area, put it there
+		$storeStatus = $this->repo->storeTemp( basename( $pathWithGoodExtension ), $path );
+
+		if ( !$storeStatus->isOK() ) {
+			// It is a convention in MediaWiki to only return one error per API
+			// exception, even if multiple errors are available. We use reset()
+			// to pick the "first" thing that was wrong, preferring errors to
+			// warnings. This is a bit lame, as we may have more info in the
+			// $storeStatus and we're throwing it away, but to fix it means
+			// redesigning API errors significantly.
+			// $storeStatus->value just contains the virtual URL (if anything)
+			// which is probably useless to the caller.
+			$error = $storeStatus->getErrorsArray();
+			$error = reset( $error );
+			if ( !count( $error ) ) {
+				$error = $storeStatus->getWarningsArray();
+				$error = reset( $error );
+				if ( !count( $error ) ) {
+					$error = [ 'unknown', 'no error recorded' ];
+				}
+			}
+			// At this point, $error should contain the single "most important"
+			// error, plus any parameters.
+			$errorMsg = array_shift( $error );
+			throw new UploadStashFileException( wfMessage( $errorMsg, $error ) );
+		}
+		$stashPath = $storeStatus->value;
+
+		// fetch the current user ID
+		if ( !$this->isLoggedIn ) {
+			throw new UploadStashNotLoggedInException(
+				wfMessage( 'uploadstash-not-logged-in' )
+			);
+		}
+
+		// insert the file metadata into the db.
+		wfDebug( __METHOD__ . " inserting $stashPath under $key\n" );
+		$dbw = $this->repo->getMasterDB();
+
+		$serializedFileProps = serialize( $fileProps );
+		if ( strlen( $serializedFileProps ) > self::MAX_US_PROPS_SIZE ) {
+			// Database is going to truncate this and make the field invalid.
+			// Prioritize important metadata over file handler metadata.
+			// File handler should be prepared to regenerate invalid metadata if needed.
+			$fileProps['metadata'] = false;
+			$serializedFileProps = serialize( $fileProps );
+		}
+
+		$this->fileMetadata[$key] = [
+			'us_user' => $this->userId,
+			'us_key' => $key,
+			'us_orig_path' => $path,
+			'us_path' => $stashPath, // virtual URL
+			'us_props' => $dbw->encodeBlob( $serializedFileProps ),
+			'us_size' => $fileProps['size'],
+			'us_sha1' => $fileProps['sha1'],
+			'us_mime' => $fileProps['mime'],
+			'us_media_type' => $fileProps['media_type'],
+			'us_image_width' => $fileProps['width'],
+			'us_image_height' => $fileProps['height'],
+			'us_image_bits' => $fileProps['bits'],
+			'us_source_type' => $sourceType,
+			'us_timestamp' => $dbw->timestamp(),
+			'us_status' => 'finished'
+		];
+
+		$dbw->insert(
+			'uploadstash',
+			$this->fileMetadata[$key],
+			__METHOD__
+		);
+
+		// store the insertid in the class variable so immediate retrieval
+		// (possibly laggy) isn't necesary.
+		$this->fileMetadata[$key]['us_id'] = $dbw->insertId();
+
+		# create the UploadStashFile object for this file.
+		$this->initFile( $key );
+
+		return $this->getFile( $key );
+	}
+
+	/**
+	 * Remove all files from the stash.
+	 * Does not clean up files in the repo, just the record of them.
+	 *
+	 * @throws UploadStashNotLoggedInException
+	 * @return bool Success
+	 */
+	public function clear() {
+		if ( !$this->isLoggedIn ) {
+			throw new UploadStashNotLoggedInException(
+				wfMessage( 'uploadstash-not-logged-in' )
+			);
+		}
+
+		wfDebug( __METHOD__ . ' clearing all rows for user ' . $this->userId . "\n" );
+		$dbw = $this->repo->getMasterDB();
+		$dbw->delete(
+			'uploadstash',
+			[ 'us_user' => $this->userId ],
+			__METHOD__
+		);
+
+		# destroy objects.
+		$this->files = [];
+		$this->fileMetadata = [];
+
+		return true;
+	}
+
+	/**
+	 * Remove a particular file from the stash.  Also removes it from the repo.
+	 *
+	 * @param string $key
+	 * @throws UploadStashNoSuchKeyException|UploadStashNotLoggedInException
+	 * @throws UploadStashWrongOwnerException
+	 * @return bool Success
+	 */
+	public function removeFile( $key ) {
+		if ( !$this->isLoggedIn ) {
+			throw new UploadStashNotLoggedInException(
+				wfMessage( 'uploadstash-not-logged-in' )
+			);
+		}
+
+		$dbw = $this->repo->getMasterDB();
+
+		// this is a cheap query. it runs on the master so that this function
+		// still works when there's lag. It won't be called all that often.
+		$row = $dbw->selectRow(
+			'uploadstash',
+			'us_user',
+			[ 'us_key' => $key ],
+			__METHOD__
+		);
+
+		if ( !$row ) {
+			throw new UploadStashNoSuchKeyException(
+				wfMessage( 'uploadstash-no-such-key', $key )
+			);
+		}
+
+		if ( $row->us_user != $this->userId ) {
+			throw new UploadStashWrongOwnerException(
+				wfMessage( 'uploadstash-wrong-owner', $key )
+			);
+		}
+
+		return $this->removeFileNoAuth( $key );
+	}
+
+	/**
+	 * Remove a file (see removeFile), but doesn't check ownership first.
+	 *
+	 * @param string $key
+	 * @return bool Success
+	 */
+	public function removeFileNoAuth( $key ) {
+		wfDebug( __METHOD__ . " clearing row $key\n" );
+
+		// Ensure we have the UploadStashFile loaded for this key
+		$this->getFile( $key, true );
+
+		$dbw = $this->repo->getMasterDB();
+
+		$dbw->delete(
+			'uploadstash',
+			[ 'us_key' => $key ],
+			__METHOD__
+		);
+
+		/** @todo Look into UnregisteredLocalFile and find out why the rv here is
+		 *  sometimes wrong (false when file was removed). For now, ignore.
+		 */
+		$this->files[$key]->remove();
+
+		unset( $this->files[$key] );
+		unset( $this->fileMetadata[$key] );
+
+		return true;
+	}
+
+	/**
+	 * List all files in the stash.
+	 *
+	 * @throws UploadStashNotLoggedInException
+	 * @return array
+	 */
+	public function listFiles() {
+		if ( !$this->isLoggedIn ) {
+			throw new UploadStashNotLoggedInException(
+				wfMessage( 'uploadstash-not-logged-in' )
+			);
+		}
+
+		$dbr = $this->repo->getReplicaDB();
+		$res = $dbr->select(
+			'uploadstash',
+			'us_key',
+			[ 'us_user' => $this->userId ],
+			__METHOD__
+		);
+
+		if ( !is_object( $res ) || $res->numRows() == 0 ) {
+			// nothing to do.
+			return false;
+		}
+
+		// finish the read before starting writes.
+		$keys = [];
+		foreach ( $res as $row ) {
+			array_push( $keys, $row->us_key );
+		}
+
+		return $keys;
+	}
+
+	/**
+	 * Find or guess extension -- ensuring that our extension matches our MIME type.
+	 * Since these files are constructed from php tempnames they may not start off
+	 * with an extension.
+	 * XXX this is somewhat redundant with the checks that ApiUpload.php does with incoming
+	 * uploads versus the desired filename. Maybe we can get that passed to us...
+	 * @param string $path
+	 * @throws UploadStashFileException
+	 * @return string
+	 */
+	public static function getExtensionForPath( $path ) {
+		global $wgFileBlacklist;
+		// Does this have an extension?
+		$n = strrpos( $path, '.' );
+		$extension = null;
+		if ( $n !== false ) {
+			$extension = $n ? substr( $path, $n + 1 ) : '';
+		} else {
+			// If not, assume that it should be related to the MIME type of the original file.
+			$magic = MediaWiki\MediaWikiServices::getInstance()->getMimeAnalyzer();
+			$mimeType = $magic->guessMimeType( $path );
+			$extensions = explode( ' ', $magic->getExtensionsForType( $mimeType ) );
+			if ( count( $extensions ) ) {
+				$extension = $extensions[0];
+			}
+		}
+
+		if ( is_null( $extension ) ) {
+			throw new UploadStashFileException(
+				wfMessage( 'uploadstash-no-extension' )
+			);
+		}
+
+		$extension = File::normalizeExtension( $extension );
+		if ( in_array( $extension, $wgFileBlacklist ) ) {
+			// The file should already be checked for being evil.
+			// However, if somehow we got here, we definitely
+			// don't want to give it an extension of .php and
+			// put it in a web accesible directory.
+			return '';
+		}
+
+		return $extension;
+	}
+
+	/**
+	 * Helper function: do the actual database query to fetch file metadata.
+	 *
+	 * @param string $key
+	 * @param int $readFromDB Constant (default: DB_REPLICA)
+	 * @return bool
+	 */
+	protected function fetchFileMetadata( $key, $readFromDB = DB_REPLICA ) {
+		// populate $fileMetadata[$key]
+		$dbr = null;
+		if ( $readFromDB === DB_MASTER ) {
+			// sometimes reading from the master is necessary, if there's replication lag.
+			$dbr = $this->repo->getMasterDB();
+		} else {
+			$dbr = $this->repo->getReplicaDB();
+		}
+
+		$row = $dbr->selectRow(
+			'uploadstash',
+			[
+				'us_user', 'us_key', 'us_orig_path', 'us_path', 'us_props',
+				'us_size', 'us_sha1', 'us_mime', 'us_media_type',
+				'us_image_width', 'us_image_height', 'us_image_bits',
+				'us_source_type', 'us_timestamp', 'us_status',
+			],
+			[ 'us_key' => $key ],
+			__METHOD__
+		);
+
+		if ( !is_object( $row ) ) {
+			// key wasn't present in the database. this will happen sometimes.
+			return false;
+		}
+
+		$this->fileMetadata[$key] = (array)$row;
+		$this->fileMetadata[$key]['us_props'] = $dbr->decodeBlob( $row->us_props );
+
+		return true;
+	}
+
+	/**
+	 * Helper function: Initialize the UploadStashFile for a given file.
+	 *
+	 * @param string $key Key under which to store the object
+	 * @throws UploadStashZeroLengthFileException
+	 * @return bool
+	 */
+	protected function initFile( $key ) {
+		$file = new UploadStashFile( $this->repo, $this->fileMetadata[$key]['us_path'], $key );
+		if ( $file->getSize() === 0 ) {
+			throw new UploadStashZeroLengthFileException(
+				wfMessage( 'uploadstash-zero-length' )
+			);
+		}
+		$this->files[$key] = $file;
+
+		return true;
+	}
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashFile extends UnregisteredLocalFile {
+	private $fileKey;
+	private $urlName;
+	protected $url;
+
+	/**
+	 * A LocalFile wrapper around a file that has been temporarily stashed,
+	 * so we can do things like create thumbnails for it. Arguably
+	 * UnregisteredLocalFile should be handling its own file repo but that
+	 * class is a bit retarded currently.
+	 *
+	 * @param FileRepo $repo Repository where we should find the path
+	 * @param string $path Path to file
+	 * @param string $key Key to store the path and any stashed data under
+	 * @throws UploadStashBadPathException
+	 * @throws UploadStashFileNotFoundException
+	 */
+	public function __construct( $repo, $path, $key ) {
+		$this->fileKey = $key;
+
+		// resolve mwrepo:// urls
+		if ( $repo->isVirtualUrl( $path ) ) {
+			$path = $repo->resolveVirtualUrl( $path );
+		} else {
+			// check if path appears to be sane, no parent traversals,
+			// and is in this repo's temp zone.
+			$repoTempPath = $repo->getZonePath( 'temp' );
+			if ( ( !$repo->validateFilename( $path ) ) ||
+				( strpos( $path, $repoTempPath ) !== 0 )
+			) {
+				wfDebug( "UploadStash: tried to construct an UploadStashFile "
+					. "from a file that should already exist at '$path', but path is not valid\n" );
+				throw new UploadStashBadPathException(
+					wfMessage( 'uploadstash-bad-path-invalid' )
+				);
+			}
+
+			// check if path exists! and is a plain file.
+			if ( !$repo->fileExists( $path ) ) {
+				wfDebug( "UploadStash: tried to construct an UploadStashFile from "
+					. "a file that should already exist at '$path', but path is not found\n" );
+				throw new UploadStashFileNotFoundException(
+					wfMessage( 'uploadstash-file-not-found-not-exists' )
+				);
+			}
+		}
+
+		parent::__construct( false, $repo, $path, false );
+
+		$this->name = basename( $this->path );
+	}
+
+	/**
+	 * A method needed by the file transforming and scaling routines in File.php
+	 * We do not necessarily care about doing the description at this point
+	 * However, we also can't return the empty string, as the rest of MediaWiki
+	 * demands this (and calls to imagemagick convert require it to be there)
+	 *
+	 * @return string Dummy value
+	 */
+	public function getDescriptionUrl() {
+		return $this->getUrl();
+	}
+
+	/**
+	 * Get the path for the thumbnail (actually any transformation of this file)
+	 * The actual argument is the result of thumbName although we seem to have
+	 * buggy code elsewhere that expects a boolean 'suffix'
+	 *
+	 * @param string $thumbName Name of thumbnail (e.g. "120px-123456.jpg" ),
+	 *   or false to just get the path
+	 * @return string Path thumbnail should take on filesystem, or containing
+	 *   directory if thumbname is false
+	 */
+	public function getThumbPath( $thumbName = false ) {
+		$path = dirname( $this->path );
+		if ( $thumbName !== false ) {
+			$path .= "/$thumbName";
+		}
+
+		return $path;
+	}
+
+	/**
+	 * Return the file/url base name of a thumbnail with the specified parameters.
+	 * We override this because we want to use the pretty url name instead of the
+	 * ugly file name.
+	 *
+	 * @param array $params Handler-specific parameters
+	 * @param int $flags Bitfield that supports THUMB_* constants
+	 * @return string|null Base name for URL, like '120px-12345.jpg', or null if there is no handler
+	 */
+	function thumbName( $params, $flags = 0 ) {
+		return $this->generateThumbName( $this->getUrlName(), $params );
+	}
+
+	/**
+	 * Helper function -- given a 'subpage', return the local URL,
+	 * e.g. /wiki/Special:UploadStash/subpage
+	 * @param string $subPage
+	 * @return string Local URL for this subpage in the Special:UploadStash space.
+	 */
+	private function getSpecialUrl( $subPage ) {
+		return SpecialPage::getTitleFor( 'UploadStash', $subPage )->getLocalURL();
+	}
+
+	/**
+	 * Get a URL to access the thumbnail
+	 * This is required because the model of how files work requires that
+	 * the thumbnail urls be predictable. However, in our model the URL is
+	 * not based on the filename (that's hidden in the db)
+	 *
+	 * @param string $thumbName Basename of thumbnail file -- however, we don't
+	 *   want to use the file exactly
+	 * @return string URL to access thumbnail, or URL with partial path
+	 */
+	public function getThumbUrl( $thumbName = false ) {
+		wfDebug( __METHOD__ . " getting for $thumbName \n" );
+
+		return $this->getSpecialUrl( 'thumb/' . $this->getUrlName() . '/' . $thumbName );
+	}
+
+	/**
+	 * The basename for the URL, which we want to not be related to the filename.
+	 * Will also be used as the lookup key for a thumbnail file.
+	 *
+	 * @return string Base url name, like '120px-123456.jpg'
+	 */
+	public function getUrlName() {
+		if ( !$this->urlName ) {
+			$this->urlName = $this->fileKey;
+		}
+
+		return $this->urlName;
+	}
+
+	/**
+	 * Return the URL of the file, if for some reason we wanted to download it
+	 * We tend not to do this for the original file, but we do want thumb icons
+	 *
+	 * @return string Url
+	 */
+	public function getUrl() {
+		if ( !isset( $this->url ) ) {
+			$this->url = $this->getSpecialUrl( 'file/' . $this->getUrlName() );
+		}
+
+		return $this->url;
+	}
+
+	/**
+	 * Parent classes use this method, for no obvious reason, to return the path
+	 * (relative to wiki root, I assume). But with this class, the URL is
+	 * unrelated to the path.
+	 *
+	 * @return string Url
+	 */
+	public function getFullUrl() {
+		return $this->getUrl();
+	}
+
+	/**
+	 * Getter for file key (the unique id by which this file's location &
+	 * metadata is stored in the db)
+	 *
+	 * @return string File key
+	 */
+	public function getFileKey() {
+		return $this->fileKey;
+	}
+
+	/**
+	 * Remove the associated temporary file
+	 * @return status Success
+	 */
+	public function remove() {
+		if ( !$this->repo->fileExists( $this->path ) ) {
+			// Maybe the file's already been removed? This could totally happen in UploadBase.
+			return true;
+		}
+
+		return $this->repo->freeTemp( $this->path );
+	}
+
+	public function exists() {
+		return $this->repo->fileExists( $this->path );
+	}
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashException extends MWException implements ILocalizedException {
+	/** @var string|array|MessageSpecifier */
+	protected $messageSpec;
+
+	/**
+	 * @param string|array|MessageSpecifier $messageSpec See Message::newFromSpecifier
+	 * @param int $code Exception code
+	 * @param Exception|Throwable $previous The previous exception used for the exception chaining.
+	 */
+	public function __construct( $messageSpec, $code = 0, $previous = null ) {
+		$this->messageSpec = $messageSpec;
+
+		$msg = $this->getMessageObject()->text();
+		$msg = preg_replace( '!</?(var|kbd|samp|code)>!', '"', $msg );
+		$msg = Sanitizer::stripAllTags( $msg );
+		parent::__construct( $msg, $code, $previous );
+	}
+
+	public function getMessageObject() {
+		return Message::newFromSpecifier( $this->messageSpec );
+	}
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashFileNotFoundException extends UploadStashException {
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashBadPathException extends UploadStashException {
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashFileException extends UploadStashException {
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashZeroLengthFileException extends UploadStashException {
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashNotLoggedInException extends UploadStashException {
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashWrongOwnerException extends UploadStashException {
+}
+
+/**
+ * @ingroup Upload
+ */
+class UploadStashNoSuchKeyException extends UploadStashException {
+}